Hi guys, got a question. Yes I know I haven't filled out a signature yet. :)

1996 Chevrolet 3500 6.5L TD
F Engine w/101,000 miles
No mods yet

Right now I am working in Iraq on trucks over here. We are rebuilding a truck that was blown up by the enemy. One of our changes is going to be 6.2L heads on the 6.5L engine that is in the truck. It is supposed to give the engine higher compression and improve performance a great deal.

Has anyone every done this on a civilian Chevy? My boss is suggesting that I put 6.2L heads on my engine w/ a rebuild kit. Is this smart? What about durability? Thanks!

I know there used to be a trick of using 305 heads on a 350 to gain low end power but upper RPMs suffered due to a lack of flow. I am guessing the same thing will happen with this scenario. Diesels don't rev like gassers but diesels need to breath more. Puting a less flowing head on couldn't possibly help a diesel. This is just my opinion, i however do not know a great deal on the 6.2/6.5's .

i don't know now... i did some reading and it seems to me the 6.5 and 6.2 heads are the same... only difference is angle of the intake manifold and threads for the injectors......

Somewhere around '90-'91 the injector angles were more vertical in prep for the turbo - you'd have interference on the turbo side if earlier than that, but the heads will interchange.

Other than that, no difference in compression, valving, anything.

The van\hummer heads are same, but will not interchange with the standard truck heads because of intake manifold bolt angles

The pre-combustion chambers - pre-cups - are specific to the 6.2, to the 6.5 n\a, and to the 6.5TD.

You can switch but there should not be a change in power. The cups are different between the two but they will work alright.

Yep - by any chance, is your boss Iraqui, or Taliban? :eek:

I have done it to a 94 with 86 heads. you will have to bend the injector lines to fit the new angel of the injector.:ro)

6.2 was built for economy.

Then along came cheap diesel and the 6.5 precups were made bigger for the turbo model.


:snipersmi :sheephump


:Get_him:



:smashfrea

Yep - by any chance, is your boss Iraqui, or Taliban? :eek:

heh.. no my boss is not an iraqi. he started thinking about it and figured that it wouldnt work on a turbo engine. he said he used to do this all the time back in the states on hmmwvs but id never heard of it. I didnt wanna even start to think about doing something to my truck that would be worthless money spent or could take away from the durability.

I want to put some of those 19.5in or 22.5in wheels on my truck and im wanting to ensure that i dont lose too much power. therefore im wanting to do the computer swap and some other things. he heard this and suggested checking into a head swap.

thanks for the info guys!

More than likely, what he was doing was swapping 6.2 hummer heads onto the 6.5, and vise versa - no problemo, there - they were n\a.

But it certainly would not have upped the power in any way - well, except if it was not running before the swap, and was running after.

Otherwise - "Pssssst, hey GI - wanna make yer hummer fly............apart?"

Welcome aboard, and hang around the forum, here, for first class info, guaranteed to make your truck live.

Take care, over there - and keep yer stick on the sand.........................