6.2 heads vs 6.5 heads

[cegusman]

Putting a 6.5 turbo on my 82 6.2. Need to change heads to allow me to run the short injectors. Have a access to a set of bare 6.5 heads, they have been magnafluxed, no cracks. Will my valves and springs from my 6.2 heads work in the 6.5 heads?

 

[mstockton]

Over the years, it seems like GM changed the valve diameter over the 6.5 years, not sure if they changed the springs or not, plus I don't think you would want to run used valves on seats they haven't worn into... you wouldn't mix the used valve on a head if you disassembled and reassembled it would you?


-Martin

 

[MaxPF]

82 6.2 will have the large valves (1.969" intake, 1.654" exhaust). Later 6.2's and all 6.5's use smaller valves (1.811" intake, 1.500" or 1.530" exhaust) in order to keep more area between the valves to help prevent cracking. You're best bet is to get a set of new valves since it will probably cost as much or more to to buy used ones and have them reground (and the exhausts must be reground with care - they are hardfaced with Stellite, and you don't want to grind through it). Also, if the valves are going in a used head you will have to have a valve job done.

Actually, the best thing is to get a set of good used heads with the original valves, but it sounds like you already have a set of bare castings...