366 TDBBC "High Perf" Heads?
 

When I had intentions of building a 366 for my truck (hey, it was free), I noticed that the factory heads had a high performance stamp on them. Isn't this kind of odd? Or is it due to the rigidity of the valve springs, rocker arm studs, etc? Beats me. This was out of an 88 C60, it was carbureted from the factory. I don't have the engine anymore, but I was just curious about this. Thanks.

Steve

Re: 366 TDBBC "High Perf" Heads?
 

366 is a tall deck big block. As far as I know, all big blocks have Hi Perf stamped on the back of them. I dont recall ever seeing Hi Perf stamped on heads except Rectangle Port heads. Peanut Port, Oval Port & Rect Port are the only heads made for BBCs. I know a 366 didnt have them based on the RPM range. 366s had a long stroke for torque not HP.

Re: 366 TDBBC "High Perf" Heads?
 

http://www.chevelles.com/forums/arch.../t-179986.html
Here is some info on Big Blocks for everyone. Not all big blocks were stamped "High Perf," but everything other than the medium/heavy duty truck blocks were. That is what makes mine so different, the number inside the heads matches up with the C60 it came from, and they were definitely the original heads, yet they had the high performance stamp.