http://www.jegs.com/cgi-bin/ncommerc...54&prmenbr=361


I'm getting ready to put together a 383 with right about 10.5:1 compression on iron heads...now obviously my concern is gonna be with detonation. I'm sure that I can get it done with some spot on tuning especially since I'm gonna be running a HSR with the 950 commander fuel management so full tunablity won't be a problem. I have a pretty fat cam for it so I know that it's gonna be bleeding off some cylinder pressure..it's 236/242 @.050 and .539/.558. But this thing from Jeg's kinda caught my eye because if it really adds additional cooling of the heads, then that can only help with detonation. But does anyone know why it say's that it's for aluminum heads and why it wouldn't work with iron heads? Any opinions would be great. Also my other option would be just changing from 64cc heads to 72cc heads and moving down to 10.0-9.5:1. Anyone think I'll have better luck going that route?

Tom

 

Wow, tough question! I'm GUESSING that since most aftermarket heads AREN'T cut for the EGR valve, this helps out? (Unless this is some race-only part where they run w/o a thermostat) Also, another idea is this. My Monte SS has a REAR cooling bypass hose from the heads and manifold. I know some Corvettes had this too and it circulates coolant from the rear instead of just the front of the intake. I kept it in place with my TPI setup too.
Detonation has a lot to do with "quench area" too. That includes the deck height, gasket thickness, and piston design. I guess if I was putting that much into the engine, I'd earn another $500, and put on a set of aluminum heads. Someone will have to do some serious work on iron heads to match an out-of-the-box set of aluminums. That's my $5 worth!