Swapping a 350 gas for a 6.5TD

[mn_powderhound]

Dear Dr. Lee

I found a picture in the gallery at Kennedy Diesel of your '84 C10. The description states that it has a new 6.5 installed. I was wondering if you could point me in the right direction for a similar project in an '86 K20. The current setup is a tired 350/350 combo and I'd like to preserve this pickup with a new engine. I was wondering what year range engine you used, electronic or mechanical injection, as well as any other tips or tricks you can offer.

Thank You
Cole

[Dr. Lee]

I had it easy, my truck came from GM in 1984 with the 6.2L diesel engine, so upgrading to a tweaked 6.5L was straight-forward.

Check in the Members Section of www.TheDieselPage.com for some good information about swapping a diesel for a gas engine.

[snoman87]

Dear Dr. Lee

I found a picture in the gallery at Kennedy Diesel of your '84 C10. The description states that it has a new 6.5 installed. I was wondering if you could point me in the right direction for a similar project in an '86 K20. The current setup is a tired 350/350 combo and I'd like to preserve this pickup with a new engine. I was wondering what year range engine you used, electronic or mechanical injection, as well as any other tips or tricks you can offer.

Thank You
Cole


I just swapped out a tired 350 for a 6.2TD ... swap is straight forward bolt in and plug'n'play for the most part. Check out my website for more information ... after that if you have any questios fire away.

[mn_powderhound]

Wow snoman, amazing writeup. I'd like to use a 6.5 instead of a 6.2 and also completely tear the old wiring harness out and replace with a new 18 circuit version so I can have power windows, locks, and extra wires for outside lights and a complete new gauge panel. Most of my factory gauges have given up. Some of my questions are, what kind of motor mounts do I need, downpipe/exhaust, and what would be a good tranny choice. I currently have the stock TH350 but I really want overdrive.

[snoman87]

Thanks ... I used energy suspension replacement mounts from a 350 and I'm running a SM456/NP241 combination ... definately need OD also. If my pocket book could afford it I'd get a ZF-6 six speed but right now I am looking for a NV4500. As for a rcommendation it all depends on your application and budget. Wwhat do you do with your truck ... tow, drag, DD or all the above? I have a 3" downpipe off the turbo to just behind the t-case and dumped. I will eventually get a complet mandrel system.

I definately recommend getting a turbo.

[mn_powderhound]

Yeah I'd like to have a good stout automatic. Main purposes of this rig are daily driver and towing/hauling.

[snoman87]

the best tranny for your application is probably the 4l80E (I think thats what it's called). Guys have posted that you can build up a 700R4 to be very reliable but I am not sure ... the cost is probably similar.

Either way you can stick with the TH350 and upgrade the tranny later. You will need a 6.2's flywheel and torque converter.

[DmaxMaverick]

the best tranny for your application is probably the 4l80E (I think thats what it's called). Guys have posted that you can build up a 700R4 to be very reliable but I am not sure ... the cost is probably similar....

The 700R4 can be built to handle high power demands, and does it very well. The "E" part of the 4L80E is Electronic. You will need a stand alone tranny controller ($$), and they come with their quirks. The 700 is not computer dependent. It only needs power to operate the TCC, which is very happy in an operator's control. I've had an upgraded 700R4 in my '85 (granted, not a lot of power) for all but the first 50K of its life. I upgraded the tranny in about 87, and it's handled all I could throw at it for 500K. This is not typical, but shows it can be done.

Just make sure you start with a late model year "K" case, and have the right parts installed.

[mn_powderhound]

Since I want to use a 6.5TD rather than a 6.2 for this application, I think a 700r will live just fine behind that as long as I use one from a newer pickup and have it built professionally with a shift kit. I could use a 4l80 and that would be ideal, however for less money I can have a 700 that will be just as strong and will not need a computer. I need to find out what year 6.5 would be the best and how to convert it from electronic to mechanical if that becomes the case. Also, I need to find out the best location for a good quality engine; rebuilt or new.

[moondoggie]

Good Day!

Didn't Jet used to rebuild 700R4's & guarantee them to 520 lb/ft? Worth looking into...

Blessings!

[mn_powderhound]

Yeah I think they do. I have a good transmission shop here at home that can build me a reliable 700r and guarantee the rebuild as well. I don't think anyone around here has done such a project before. The GM 6.2/6.5's are not very popular around here. But I dare to be different

[mhagie]

I have done this conversion also and it wasn't that hard to do,
I am using a 700R4 from Bow Tie overdrive ,www.700r4.com and i like it.
of course mine was older so the wiring was a bit more of a challange but not that hard to overcome.
Merle

[snoman87]

I need to find out what year 6.5 would be the best and how to convert it from electronic to mechanical if that becomes the case.

For drop in and go get a 92'-93' 6.5

Here are my thoughts if you need to buld one....
599 casting block, 97+ 6.5TD heads, mechanically wastgated turbo, and 97'+ 1Ton cooling system, DB2-4911 pump. Add a Stud girdle kit and gear driven timing

To convert from electronic and mechanical is probably the easiest to do. Get yourself a DB2-4911 Injector Pump and hard lines. Remove the DB4 and lines from a 94'+ 6.5TD and install the new pump and your ready to prime and go :)

[mn_powderhound]

Thanks for the info snoman. Well I hate to say this, but I've got another wild idea. Not sure exactly how costly it might be yet, but I found a shop that does cummins 6bt swaps. If I use that instead, with just a few minor mods the 6bt can make more power than almost any 6.5 ever would without giving up reliability.

[snoman87]

Thanks for the info snoman. Well I hate to say this, but I've got another wild idea. Not sure exactly how costly it might be yet, but I found a shop that does cummins 6bt swaps. If I use that instead, with just a few minor mods the 6bt can make more power than almost any 6.5 ever would without giving up reliability.

That's not a wild idea ... that's the way to go :) If I had the cash I would have gone that way to start with.

http://coloradok5.com/forums/showthread.php?t=121702

http://www.turbodieselregister.com/forums/showthread.php?t=136977

[mn_powderhound]

My only trouble with that is finding a donor Dodge. It's best to find a complete pickup, like one that's been t-boned or something and I want to use the 2nd gen engine. So like '95-up. The other problem is I currently have and auto and I don't really want to switch to the NV4500. It's a good tranny, but then I gotta swap steering columns and cut another hole in the floor.

[snoman87]

I too had the same issue but for me it was that I couldn't afford to buy a donar truck ($3500-$7500 cdn) ... so I swapped in a 6.2 and Turbo'd it. Looking back I am probably $1000 shy of what I could have picked up a donar truck for.

If you get that p30 step van adapter then you can use any GM bellhousing ... now will a 700R4 stand up to the torque of the 6bt?

[mn_powderhound]

For a 700r to live happily behind a cummins, it'd have to be heavily built. I'm thinking in order to have a good strong overdrive auto, you'd need to look towards a 4l80 and then have to wire up a stand alone computer. That's another dilemma of mine, and I deffinatly will not install a dodge auto.

[snoman87]

It's expensive and lots of work any way you look at it ... isn't it :)

[trbankii]

If you're going the Cummins route, check out MoeDog's thread:
http://www.thedieselpageforums.com/tdpforum/showthread.php?t=1519&highlight=moedog

[mn_powderhound]

Well now that I know the approximate cost of having Ken do the conversion, it'd probably be best off in the long run to have him do it. I'd probably be money ahead. With this route, the power output will be way above any 6.5 and probably longer lasting too. Now my only other problem is to replace the cancerous rotting body

[snoman87]

That's easy compared to swapping engines :)

[mn_powderhound]

Yeah it's easier than doing engine swaps, but deffinately not cheap. Also trying to find good straight non rusting cab. Mine was tboned a few years back and the body man deffinately did not put things back to where they belong, so rather than cut that all apart again, I want a new cab. I also need a good straight box minus a wavy floor.

[ColstripMike]

:eek: :eek: First Post, guys:
The basic premise is the same. Should my 'donor vehicle' be a van, or can I use a Pickup/Suburban?
Current specs are: 2001 G 3500 155" 15 pass van. Vortec 350, 4L80E, 4.10 gears, tow platform(seldom used) 'heavy-duty' emissions sticker under the hood. About 55000 miles, 25000 of which are Hiway @ 65-75 MPH. Runs about 40% loaded most of the time, getting 13.9-14.5 mpg @ 66-68 mph.
I understand that the torque converter will need changed, I already have Hydro-boost brakes, and I'd like to keep the A/C. I know from the GM bobybuilders website that the van's diesel exhaust has a converter and muffler

[ColstripMike]

I briefly looked at a Dodge Cummins, but the physical size of the thing is a HUGE stumbling block, and under-hood room is at a premium in a van.
I know I'll have to have a few things specifically for the van, bu could a 97-99 Sub/Pickup work for the rest?

Thanks. Mike from Colstrip USofA

[More Power]

Colstrip,

How much do you know about the similarities/differences between your 2001 van and the 2005-06 models?

The reason I'm asking is because if there are few differences, and if they all use the same underhood wiring harnesses, fuse/junction/electrical boxes and general hardware layout.... it might be easier (and cost no more) to swap in a used Duramax with van ECM/programming. It'll work with your 4L80-E.

However, if there are substantial differences in the electrical/mechanical systems, the best engine swap choice might be different. For example, it's relatively easy to swap a Duramax into any 1999 or newer (GMT-800 body style) gas powered pickup or SUV because the basic systems are there to support the Duramax once the diesel specific parts are obtained. It's nearly plug-n-play.

Jim