Call GM performance and they should know who makes them, On my Ford i run 1.8 SVO rockers that are made by Crane. Sounds like you got a real strong combo going into your motor, 800 HP? AFR makes some damn good heads, wish they made 'em for BBF! When you get it all to gether let us know how it runs. I notice your avitar, what lake do you run on? Maybe run into ya sometime.