Hi everyone, I am currently restoring a 1981 firebird formula, but the engine I bought for my car is out of a 1989 caprice, it is casting code 14093638. I wanted to make a 383 with the edelbrock performer rpm package, especially since the block is a roller cam block and they have a roller cam for the package. When I checked out he heads though, they say that they are for blocks up to 1986, can I still use these heads on the 89 block or do i have to go with vortc intake and heads?