Hey guys, I'm looking to gather some info on a project I'm putting together for my gf. The truck its going in is a 86 K20, has a 350/TH400 now but I want to do a 6.2/6.5 TD re-power. I want to have mechanical injection and I'm assuming the DB-2 on the 6.5 is the one I would want correct? From what I have found I want the F code intake and 96.5+ cooling. Should I just get a 6.2 and replace the pump, intake and cooling and use a 6.5 exhaust/turbo (heads too?) or use a 6.5 block with the above upgrades and J code heads? I know I should get a 599 block and stay away from blocks with piston squirters because they are weaker. Also are the internals different besides the bore diameter? Basically assuming they all have the same later DB-2 pump, 96.5+ cooling, F code intake, and turbo what is the better combo 6.2 block/J code heads, 6.2 block/F heads, 6.5 block/ J code heads, or 6.5/ F code heads? Thanks guys.