Originally posted by 1stGenCamaro
Hmm, since there is no sure way to tell from the casting numbers if it is a 4 bolt block or not, I'll just have to rip off the pan to find out. Thanks for the help, I did get the casting number off the block which was 361959, just a 73-85 casting, same with the 113 cc smogger heads. The engine has no EGR and its carbureted at the moment. I had heard it mentioned before on other sites, just couldn't remember where. I know what Hi-perf means....just not what it meant on this block; mains, steel crank, good rods, etc.
Unfortunately HiPerf does not necessarily mean it. Nor does it mean you get forged cranks with 4 bolt mains or hi performance rods, heads, yada.

It sounds as if you have the engine in a vehicle. These things make a ton of torque up to 4500 rpm which is fine for a street vehicle around 3500 lbs. If you want more performance you'll have to take it out and tear it down. Then you'll know what you have and what needs replacing from a worn or performance standpoint.