6.5L heads

[sht2kll]

Howdy all: I read somewhere on a previous thread about using 6.5L heads on a 6.2L. Can someone tell me the benefits of this? Thanks. Tom

[More Power]

Howdy all: I read somewhere on a previous thread about using 6.5L heads on a 6.2L. Can someone tell me the benefits of this? Thanks. Tom

Most people install 6.5 heads on a 6.2 shortblock because it makes it easier to use a 6.2L shortblock in a truck/Suburban originally equipped with a 6.5 - i.e. the 6.5 fuel injector lines and the turbocharger related components will fit better.

If I were building a 6.2 for a 1980s truck/Suburban, and could choose between a perfect set of late 1980s 6.2 heads and a perfect set of mid 1990s 6.5TD heads, I'd choose the 6.2 heads if I wanted better fuel economy or I'd choose the 6.5 heads if I were more interested in max power. You'd need matching fuel injector lines for each choice. There can be up to a 25% difference in fuel economy potential between head sets and possibly up to a 10% difference in maximum power (when all other fuel injection and turbocharger system components are also chosen for maximum power).

Jim

[sht2kll]

Thanks for the info. I also noticed that people are using 6.5L injector nozzles on the 6.2L engines. I take it you would have to increase the output of the IP in conjunction with doing this? Is the gain that much to justify doing it? I have always understood that it is about volumetric efficiency. Just adding more fuel will only go so far without changing the cam(s) or working the heads to help flow. then other things have to be modified to handle the HP and torque gains. I guess on a naturally aspirated 6.2, every little bit helps. Tom