6.5 heads on 6.2 block?

[southdave]

6.5 heads on 6.2 block? Has anyone done this and how did work out?
what I belive true
1. Less mpg with the 6.5 pre-comb. chambers
2. Intake vavles are larger

do I use the the 6.2 cam and push rods or 6.5??
note I have a gm4 turbo on it?

 

[gimpyrobb]

Are you asking this question because you are a "block head"?

 

[southdave]

Are you asking this question because you are a "block head"?

Gumby dammit

 

[southdave]

here

 

[nf6x]

When my HMMWV developed cracked heads many years ago, the guy who fixed it for me put on 6.5 heads that he had available. I recall that he had to replace the injection lines with a different set, but I don't recall whether he had to change anything else. I was at home about 250 miles away while most of the fixin' was happening. I didn't notice a difference in MPG or power, but I was still getting to know the truck and working out bugs, so I wouldn't have noticed anyway. So, I guess that all I can really add is that it worked, and my truck still runs.

 

[chevyCUCV]

I think the precups are better matched with the turbo, but i could be wrong there.
I dont know about the valves, only read that 82's had larger intake valve.


But yes you can bolt them on and go.
What kind of head gaskets are you planning on? Victor Reinz is the top of the line

 

[pigfoot63]

Done it alot. Injectors are shorter and angle they set is different. You can make the 6.2 lines work but you are better off changing them.

 

[southdave]

will 6.5 cam lifters ect.. going to be need

 

[patracy]

The cams will interchange but they're different. The 6.2 has more lift and overlap than the 6.5 cam. (6.2 cam has .472" lift)

 

[southdave]

The cams will interchange but they're different. The 6.2 has more lift and overlap than the 6.5 cam. (6.2 cam has .472" lift)

So I assuming that lifter and the push rods are the pretty much the same?

 

[jdknech]

i have put 6.2 heads on a 6.5.. and i just had to rebend the fuel lines.. and the 6.2 heads give my 6.5 MUCH more power... for what ever thats worth...

 

[condor418]

i know i read some where not to bend the lines because of some coating on the inside that cracks off and fouls up the injectors. just a heads up

 

[jdknech]

thanks for the heads up, but I have put close to 5K miles on it with no injector problems as of yet... i replaced the injectors when i did the heads, with 40hp marine injectors..

 

[condor418]

jdknech did you notice a difference in power with the injectors?

 

[southdave]

FYI
6.2 heads made after 1990 (humvee take out) are the same casting as 6.5 whether the internals are change ie cam lifter push rods., where same I don't know as of yet for the N/A motor the turbos run a different cam.

 

[chevyCUCV]

i know i read some where not to bend the lines because of some coating on the inside that cracks off and fouls up the injectors. just a heads up

Ya just like the "82 red block" is a better casting than all other gms blocks

Internet Myths

 

[jdknech]

jdknech did you notice a difference in power with the injectors?

i did not notice any power difference when i put in the injectors, i put them in a month before i blew the heads, but they did make it run better, and better MPG.. from my research it seems the to get power from the bigger injectors, you have to "chip" the computer... thats next on the list (i already have 4" dimond eye exhaust, the injectors, custom 4" intake to the turbo... all i have left to do is a HX35 turbo, camshaft, and chip )

FYI
6.2 heads made after 1990 (humvee take out) are the same casting as 6.5 whether the internals are change ie cam lifter push rods., where same I don't know as of yet for the N/A motor the turbos run a different cam.

from what i can tell you are correct, but the heads i used were off of a J-code CUCV take out (parts engine for the M1009, or M1031 that i have)