new guy with some 6.2 questions

[Islander]

Hi--I'm new to this board, and pretty new to the 6.2 liter world. I've been wanting for some tome to put a 6.2 into a (full size) Jeep Cherokee. I have a donor vehicle--a 1983 Chevy pickup with a 6.2 and 700r4. I also have a government surplus 6.2. Is one of these engines a better candidate for rebuild than the other? I have heard that "J" type engines are better in some way than others. How can I identify whether my government engine is a J-engine?
Thanks!

[john8662]

There are so few differences between the C and J engine that it won't matter. The engines are identical internally, the difference comes in the intake used, the lack of an exhaust flapper and a free flowing intake manifold. You can identify the difference by looking at the intake. the J intake will be a dual plane intake. The C intake will have a port smack dab in the middle that usually still has the EGR valve sitting on top of. Either engine will make a great rebuilder, just be sure to pull the oil pan before you invest any time or money into the block, you'll want to look for main webbing cracks.

[C.K. Piquup]

Is the surplus vehicle military/CUCV?If so,and original,it would be the better block due having a higher-nickle content block.

[Islander]

So far as I can tell, the engine came out of a Humm-vee. I say this only because it has a strange hub on the front of the water pump pulley that is just like one I saw in an Army Hummvee. The intake has no obstructions, and it has headers rather than exhaust manifolds. I have taken it apart down to the bare block, and I have found no cracks around the main bearing webs.

[CleviteKid]

Sounds like a genuine Military Humvee engine. If you are REALLY adventurous, pull the heads and check to see if the original cross-hatching is prominent in every cylinder bore.

Dr. Lee :cool:

[Islander]

Well--I only paid $150.00 for it--because it was frozen solid! I had to soak thetop ends of the cylinders and pistons in oil a few days, then force the pistons out. There is still cross-hatching half-way up the cylinders, but the tops are still pretty rusty. I'll probably reuse this block, but it will have to bored to clean up the cylinders.