6.5 to 6600 OR new & better 6.5

[TGVet]

Well its been quite a while since I was on TDP. Since my 95 K2500 Sub went kapooy at 476K back in 05, I was forced to make an immediate decision on another rig ASAP. After testing them all, I settled on a new 3500 Ram QC now with 239K on it and I became a TDR member. But I'm really missing my Sub and now getting close to giving it a new heart which brings me back to TDP for questions and answers hopefully from very reliable sources. Of course opinions are welcome, but the raw facts are what I really hope to find here from those having done what I decide to do.

I was originally going to convert to a 6600, bought Jim's book when it came out on the whole process, came very close to buying a LBZ & matching trans until the bottom fell out of the market and my industry. In hind sight, perhaps I'd been better off at just flipping for another 6.5 right away and get the rig running without a big to-doo. I investigated 6.5 perf. option engines I found via here, even contemplated a 5.9 for it, but I think the 5.9 is best kept for the Dodge frames.

So here's my questions:

Should I opt for the 6600 LBZ or yet a later LBxx ?
Should I opt for a precision built 6.5 with the max HP that is possible either something out of BC or from a local source in Washington or ??

It's been a while since I read up on the Canadian built 6.5 block and I haven't been keeping up on the 6600's of late either. Few years back I found an LBZ & matching tranny w/harness and ECM w/66K on them for $9,600.00 plus freight. Not a bad price. I don't know where the best place to start looking again if I go that route other than a local yard so, if anyone has some info on that as well, I will look forward to it.

Thanks for any feedback..

[More Power]

If "simple" and "best" are combined into one question, I would have to say the new AM General P400 6.5 would be my answer by a wide margin. It's as bullet-proof as a 6.5 can be, and offers the best platform to build an excellent power package for any factory-rated Suburban use.

There are so many questionable vendors out there offering all sorts of questionable products that it's hard to wade through them all. China has made the situation much worse than it was just a few years ago, regarding recommendations for products and vendors. Every week I hear from others how some sort of Chinese auto part has failed in a cheezy sort of way. I even have my own story about a front hub/bearing/ABS sensor replacement I installed (briefly) on my daughter's car that was purchased from a major auto parts house - but turned out to be made in China.... A total piece of crap that didn't work, but cost a lot....

Stick with vendors who we know and trust. They have a reputation to uphold and have demonstrated a commitment to the community.

Jim

[TGVet]

If "simple" and "best" are combined into one question, I would have to say the new AM General P400 6.5 would be my answer by a wide margin. It's as bullet-proof as a 6.5 can be, and offers the best platform to build an excellent power package for any factory-rated Suburban use.

There are so many questionable vendors out there offering all sorts of questionable products that it's hard to wade through them all. China has made the situation much worse than it was just a few years ago, regarding recommendations for products and vendors. Every week I hear from others how some sort of Chinese auto part has failed in a cheezy sort of way. I even have my own story about a front hub/bearing/ABS sensor replacement I installed (briefly) on my daughter's car that was purchased from a major auto parts house - but turned out to be made in China.... A total piece of crap that didn't work, but cost a lot....

Stick with vendors who we know and trust. They have a reputation to uphold and have demonstrated a commitment to the community.

Jim

I recently had all new brakes and rotors put on my Ram, parts from Auto Zone (rotors) were lifetime warranty and made in China not the pads though. I was reluctant to buy them but my mechanic said they were "OK" and of course less $$ than US made. We shall see how well they hold up. Otherwise, I do my best to avoid anything NOT US made and especially from the ChiComms.

I've been saying it for decades and stand by it "China is our worst enemy" and even though they are beating us in the trade war we in with them, we haven't seen anything that's yet to come. The "sleeping giant" I fear is in a coma and deaths door and unless WE WAKE UP to that fact, we're doomed.

That aside, thanks for the feedback Jim, I will investigate the new P400 and find out what it has to offer as compared to the old 6500 GM. I'd like to get 300HP vs the old stock 195 without having to go wild with parts, but having lost touch with that power power plant, perhaps now there are newer mods for it.

Rob

[THEFERMANATOR]

If your looking to do a 6.5 swap, here is about as good as you will find. http://www.thedieselpageforums.com/tdpforum/showthread.php?t=34348 This my 95 BURB converted to an LB7/ALLISON combo. Keep in mind that an LBZ will most likely require a body lift or cowl hood to clear unless you build up a custom intake set-up for it. Personally if I had it to do over again, I would have done a new style 6.5 from GEP(the diamond block) with an ATT on it. I would have spent THOUSANDS less, and had a good deal of power, not as much as I have now but more than enough regardless.

[Edahall]

The 6.5L from GEP would be by far the easiest swap. The other swap that would still be easier than the 6600 Duramax would be the 88-93 6BT VE Cummins or 94-97 P-pump Cummins. All the parts needed to do the conversion such as engine mounts and pulleys to put into a Chevy are available. However, automatic transmissions don't seem to hold up too long behind a 6BT Cummins especially when power output is increased from stock or lots of money is spent to build up the automatic transmission. For this reason, I chose manuals on my Cummins conversions.

[TGVet]

If your looking to do a 6.5 swap, here is about as good as you will find. http://www.thedieselpageforums.com/tdpforum/showthread.php?t=34348 This my 95 BURB converted to an LB7/ALLISON combo. Keep in mind that an LBZ will most likely require a body lift or cowl hood to clear unless you build up a custom intake set-up for it. Personally if I had it to do over again, I would have done a new style 6.5 from GEP(the diamond block) with an ATT on it. I would have spent THOUSANDS less, and had a good deal of power, not as much as I have now but more than enough regardless.

WOW ! I am exhausted from all that and haven't twisted wrench one. There's no way I'm going to do the Dmax now and its not that I don't enjoy a challenge as my daily work life offers that. I suppose if I were an auto mechanic instead of an electrical contractor with a nice shop to work in and all, I'd go for it, But I just want to get my Sub going again ASAP and as much as I would love to have Dmax power my stocker had enough for the ten years and 476,000 miles I put on her to get me by. I'm going to further investigate the newer 6.5 option and hopefuly get the sub in my friends shop this winter for the transfer. BTW, what is the ATT you refereed to ?

I commend you for an awesome job well done.

[THEFERMANATOR]

WOW ! I am exhausted from all that and haven't twisted wrench one. There's no way I'm going to do the Dmax now and its not that I don't enjoy a challenge as my daily work life offers that. I suppose if I were an auto mechanic instead of an electrical contractor with a nice shop to work in and all, I'd go for it, But I just want to get my Sub going again ASAP and as much as I would love to have Dmax power my stocker had enough for the ten years and 476,000 miles I put on her to get me by. I'm going to further investigate the newer 6.5 option and hopefuly get the sub in my friends shop this winter for the transfer. BTW, what is the ATT you refereed to ?

I commend you for an awesome job well done.

ATT=A team turbo. It is an aftermarket non wastegated turbo that seems to be working well for the majority of 6.5ers with a tune for it. I've ridden in a 6.5 with one, and let me just say you would not have guessed it was a 6.5 powering it. He did have alot of other supporting mods done to it as well, but it was impressive to say the least. If your after a quick swap in a hurry, then the DMAX is not for you. I'm sure even Gordon who did his 99 2WD would agree with me on this one as well. An experienced wrench should expect to spend close to 100 hours if I had to guess to do a DMAX swap and make it fully functional and not look like it was slapped in. I have close to 400 hours in mine, but I did ALOT of other things when I did the swap as well. I will say over 2 years almost 25K miles later, she still amazes me at the power she has and is going strong.

Don't count out a new style 6.5 though. AMG made ALOT of improvements when they came out with the OPTIMIZER drop in replacement, and took it even furthur when they built up the P400(it isn't a direct drop in though as it requires a custom oil pan I believe to make work).

[bshull]

Just finished my own P400 swap in my 95 burb. I only have about 2300 miles on it but so far everything is good!

The P400 is not an exact "drop-in" replacement. If you have 4 wheel drive you will need to have the oil pan modified. The bell housing bolts are metric. I also had to find new exhaust manifold bolts, the new manifolds were just a bit different.

At the same time I also changed engine/tranny mounts, installed high output water pump, installed dual thermostats, new exhaust manifolds, timing gears, marine injectors, and new oil cooler.

I purchased the engine from Penninsular and they have a process to modify the oil pan. The pan is made from cast aluminum so unless you are good working with that I recommend having someone else do it for you.

I am also running an ATT with a Heath tune.

I just returned from a business trip, 1900 miles, the engine performed great, no problems. The engine oil still looks clean after the trip!

If properly set up the p400 will have enough power for the normal suburban owner. The p400 is rated for more horsepower and torque than a regular 6.5. Since my only horsepower/torque improvements are new tune, cold air intake, 4in exhaust, and ATT I do not think I will be in any danger of overloading the engine and breaking something.

If you need more power you could order it with 18 to 1 pistons and crank up the boost and fuel.

It was a lot of money, especially for an older vehicle, but there is nothing like a diesel burb going down the road :D. Would I do it again? Yes.

Brian

[TGVet]

Just finished my own P400 swap in my 95 burb. I only have about 2300 miles on it but so far everything is good!

The P400 is not an exact "drop-in" replacement. If you have 4 wheel drive you will need to have the oil pan modified. The bell housing bolts are metric. I also had to find new exhaust manifold bolts, the new manifolds were just a bit different.

At the same time I also changed engine/tranny mounts, installed high output water pump, installed dual thermostats, new exhaust manifolds, timing gears, marine injectors, and new oil cooler.

I purchased the engine from Penninsular and they have a process to modify the oil pan. The pan is made from cast aluminum so unless you are good working with that I recommend having someone else do it for you.

I am also running an ATT with a Heath tune.

I just returned from a business trip, 1900 miles, the engine performed great, no problems. The engine oil still looks clean after the trip!

If properly set up the p400 will have enough power for the normal suburban owner. The p400 is rated for more horsepower and torque than a regular 6.5. Since my only horsepower/torque improvements are new tune, cold air intake, 4in exhaust, and ATT I do not think I will be in any danger of overloading the engine and breaking something.

If you need more power you could order it with 18 to 1 pistons and crank up the boost and fuel.

It was a lot of money, especially for an older vehicle, but there is nothing like a diesel burb going down the road :D. Would I do it again? Yes.

Brian

Thanks again to all for the info.
Edahall mentioned the GEP, please expand what that is ?? (acronyms..lol)

Iv'e read about the AMG, and have known about the Peninsular and Heath's works. Also, in Auburn,WA is Stan's Headers & Exhaust http://www.stans-headers.com/ he's done work for my Sub years back and I would look to him again for any manifolds, 4" tubes, mandrel bent crossover etc..

Peninsular's marine 6.5 @400HP looked interesting but if I remember it was pricey.. I think they offered 20:1 pistons too vs the factory 22 if memory serves.. Mind you, its been several years since I was reading and keeping up on GM stuff since I parked it and became a Cummin's snob. lol NOT without condemnation, I'm not going to get started on my non-engine (so far) Dodge issues here though, that's for TDR.

I also installed Yukon 3:42 diff's years back, AFE intake, the Ottomind chip and some other minor mods. I think it would be great if there was a way to bolt up a 5-speed but don't know if that is a feasible option.

Has anyone swapped out the rear drums (or axle) for disks ? I would rather have that and upgrade to 17 or 18's.

Also mentioned a few threads back was the "Diamond", w/o having searched that, is that the block w/the machined crank vs cast ?

Are there aluminum heads for the 6.5 ? I took the passenger side head off after it sucked a valve and that thing must have weighed nearly 50-75lbs.. what a beast..

Thanks again for responses.

[THEFERMANATOR]

No auminum heads that I know of. GEP is general engine productions which is who is building the new 6.5's for the military, and I believe they are the same company as AMG.
There are disc brake conversions for the rear, but I don't personally see the need. there is a TSB that gives you the part number for updated rear shoes and a new proportioning valve that DRAMATICALLY improves rear brakes(I did this to mine and noticed an IMMEDIATE difference, i can no longer power brake it and light the tires as the rear brakes HOLD now). The diamond block is the new blocks cast since about 01 by INTERNATIONAL(the actual NAVISTAR corporation, not the imitator out of new york). The NAVISTAR/INTERNATIONAL castings use tehre emblem cast into the lifter valley under the intake which is 2 triangles back to back that form a diamond. These are the new and improved 6.5 blocks. The engines with the forged cranks are the new P400 engines that are not a true drop in, but is doable as bshull has done one as well as others.

[TGVet]

Hello bshull, Hows you P400 doing ? What MPG are you getting ? I hope to install a new one in my 95 Sub and possibly the L485E they offer too.

[TGVet]

Just finished my own P400 swap in my 95 burb. I only have about 2300 miles on it but so far everything is good! Brian



Hows your P400 doing ? What MPG are you getting ? I hope to install a new one in my 95 Sub this summer and possibly the L485E they offer too.

[HH]

I have over 120,000 miles on my GEP engine I bought from Peninsular several years ago, it was a worthwhile investment. I have an 18:1 engine and I am using a GM8 turbo.

[bshull]

The motor is running fine, no complaints. I think I have about 15,000 miles now.

My MPG will vary depending on where I have been, if most of the driving is 55 mph to 65 mph I can expect 18 or so MPG. If my driving is on the interstate 70 to 80 mph I can expect low 17 mpg. If I am pushing a strong headwind at 80 mph I will get mid to upper 16s. Most of my interstate driving will put my RPMs above 2000 and up to 2400.

Around town I will get 15 - 16 mpg.

Keep in mind I am usually carrying about 1000lb of tools in the back and when I am on the road I have a very heavy foot and use it often. I am also running an aggressive goodyear wrangler tire tread (put those on for the snow that did not arrive this winter). I am thinking my next tire purchase I might upsize the tires to change the final drive ratio to see if I can get my RPMs down in cruise.

For the age of the vehicle and my driving style I am happy with the mileage. I could get better if I were willing to slow down and not push the gogo pedal as hard.

Brian

[cjones]

So, I need to ask some stupid questions about the P400 or 6500 engines.
1. Does GEP offer an improved Injection Pump? I ask this because one of the main issues with the engine was the block but the other is the IP.

2. Does GEP use International, Diamond, blocks or is international a seperate company?

Thanks

[Vin82k3500]

P400 in 82 K3500 well not sure of all aplications but my P400 was a drop in in my older body style truck if you were gonna off road it you would probably want to lift it for clearance as the oil pan does hang kinda low the hardest part of my swap was adapting the 6.2 oil cooler lines and making the 17 mm headed 10 mm bolts fit on my aftermarket bellhousing required to make my dodge nv4500 gearbox fit in this old truck with out a lift kit I used the db2 4911 IP from my 6.2 wich origanlly came off a 93 6.5 TD before it was rebuilt by Connell Diesel in Portland Maine it is not turned up i believe it was backed of 3 flats since I am running this with no turbo and in a truck the weighs signifigantly less than 3 tons dual exhaust streight piped 2.5 inch runs strong low egts plenty of power not a ford guy but this thing feels like a 6.9 or 7.3 idi for power I would enen consider it comparable to first gen power levels stock levels on all those engines it deffinately feels head and shoulders about the level of my old 6.2 simly put my 6.2 felt like a mild 305 my p400 feels like a mild 396 as for mileage I am averaging 26 mostly country roads top speeds of 55 to 60 mph nv4500 has .73 od have 4.10 gears standard load 265s alloy wheels low rolling resistance very fun to drive if I want to pass somone drop back a gear and 1/4 throttle it will get from 55 to 85 like my little nissan maxima quick very satisfied with this engine in my truck and more so that I did this as opposed to cummins of d max since I used all original accesories from my 6.2 plus those I had upgraded.

[greatwhite]

So, I need to ask some stupid questions about the P400 or 6500 engines.
1. Does GEP offer an improved Injection Pump? I ask this because one of the main issues with the engine was the block but the other is the IP.

2. Does GEP use International, Diamond, blocks or is international a seperate company?

Thanks

1.No. But stanadyne does. Get the latest model from them and you get ceramic bits where it matters to help cope with ulsd.

2. International is a seperate company. Navistar if you want the parent company name . GEP is "general engine products" and is owned by american general (AMG). GEP lacks the engine foundry to cast thier own block and heads, so it was contracted out to international which have thier own foundry.

The "diamond" people are referring to is merely the company logo and its cast into the lifter valley. It's two triangles back to back so it looks like a diamond when it's cast on the block. If you google "international logo" you will see it. It's just one of the ways (easiest way) to identify a block cast by international.

These are accepted as the best 6.5 castings to date. There is a "regular" 6500 Optimzer and a "p400" optimizer.

They're both optimizers.

A p400 is recognizable by a casting number "p400" cast into the block and the large lower end "girdle". It also has a forged crank, but there's no real way to tell this from the outside. The rest is the same as a 6500 optimizer(ie: heads, con rods, pistons, etc).

The regular 6500 optimizer is a straight drop in. I have one in my 98.

The p400 optimizer needs a custom oil pan to fit in a 4x4, but is otherwise a drop in.

[Vin82k3500]

on my older truck there is noting under the oil pan unless you have an inline 6 maybey this is why mine was a drop in I do know as far as that goes it is not the case in newer ifs trucks