These are parts that I bought for my 1989 Pontiac Firebird Formula. I recently sold the car, but the buyer didn't want to spend the extra money for these. The current price for the heads is $1200, but I bought them when they were $900. They are centerbolt heads. The headers are for cars with dual cats or you could fabricate new head pipes. I don't think Edelbrock makes those exhaust parts anymore, they seem to be more into carburetors now. I would sell everything for $1250.