new to site but i have a question

[73hillbillyk10]

what would be a good combo for my 73 chevy 4x4 a turbo 6.2/sm465 or turbo 6.5/nv4500 with 3.73s and 33 inch tires what would be better truck would be used for trail wheeling, dd, and some trips fron RI to Maine/NH/VT and what mileage would is see from each combo thanks

[NH2112]

IIRC 1st gear is pretty similar between the 2, and with 33" tires & 3.73 gearing you may not find many opportunities to use 5th on an NVG4500. Still, I think I'd go with the 6.5l/NVG4500 since you may end up wanting to drop your gears. 3.73 is pretty tall for 33s, IMO. With an OD tranny I'd have 4.56s for approx. the same final drive ratio in 5th gear.

[73hillbillyk10]

ok then from a reliability standpoint what is better the 6.2 or 6.5

and i was thinking 373 to keep the rpms down if i went with the sm465?

[NH2112]

My experience is that the 97-up blocks with oil squirters often crack around the nozzles, so I'd look for a 94-96 and use a mechanical injector pump delivering the stock 190hp at most. I'd pick a 6.5l over a 6.2l mainly because the block webs are thicker (except for the last few years of the 6.2l) and they use 10mm instead of 12mm main bolts, putting more metal in the formerly crack-prone outer main bolt hole areas. The one-piece rear main seal is nice, too (also found on late 6.2ls.)

[73hillbillyk10]

so next question is what would gas mileage be like

[Robyn]

With a 6.2 N/A the mileage can be around 22-24 Hwy
The 6.5 turbo will generally be around 18-20 max

The early 6.5 blocks 929, 599 are about the best unless you get into the real late AMG stuff.

The 97 squirt blocks were junk. I had one with very low miles and it broke through the number 4 main squirt hole and up into number 8 cylinder.

A constant loss of coolant and sloppy oil was the tip off.

Sadly the engine only had about 50K on the clock.

Replaced the block with a 929 casting.
Bored it .020" OS, fresh pistons, rings, bearings.

Slightly used but rebuilt heads with the "T" precups.

The 6.2 Blocks of the early years are fine.
Any of these engines can crack main webs, even the real early red blocks.

The late 6.2's of around 89-90 on went to the one piece rear main and use the same crank as the 6.5 does.

The late 6.2's also use the same block but with the smaller bores.

Many late 6.2's had the 599 block casting.

The 6.2 can be turboed with the GM parts off a 6.5 or use a Banks or ??? kit.

If you turbo a 6.2, use a 4911 pump from a 92-93 6.5 PUMP or turn the J 6.2 pump up 1/4 turn or so.

Just some thoughts.


Missy

[73hillbillyk10]

sweet i was thinking turbo for the low end grunt wheelin and highway merging but ill look into the casting #s this site is great

[K5-CJ5]

The NV4500 is a great tranny but for hardcore wheeling when you do not need the 5th gear I would stick with the SM465 transmission. The SM465 has a lot of great options for t-cases without costly adapters, and is near bullet proof on the trail.

I would do a 6.5 TD/SM465/ with either an atlas II or a 203-205 doubler.