Difference between ZZ4 and regular SBC I currently have a 91 TPI 305 and was thinkin about gettin the ZZ4 what are the differences between the engine and the 87 and later SBC?

 

Both have roller cam and one-piece rear main seal.

The ZZ4 has hypereutectic pistons and PM rods, regular has cast pistons & rods.

ZZ4 also has a better oil pump and a pan baffle.

The ZZ4 heads are aluminum with 58cc chambers and no exhaust cross-over passage (like the Vette L98).

 

You will need to have the two center bolt holes on the 91 305 TPI intake milled to fit the olderstyle heads of the ZZ4. Or you could just pony up and get an aftermarket intake. The Edelbrock comes milled for both type heads. Everything else bolts up.
My ZZ4TPI combo just passed 40K miles.

 

if I only use the ZZ4 block would I should be able to use the centerbolt valvecover style heads then? I am looking into it as a foundation for my project cause I want to use AFR heads a Mini-Ram, or LT1 manifold and I want to have a good foundation

 

I'd imagine any SB head for a SBC I would work on the ZZ4 block.