CK5 - The Full-Size GM Off Road Community

Post deleted by Dune_Goon

Dune Goon, I don't think there is such a thing as a "Vortec block." There are Vortec heads, which will bolt onto a generic Chevrolet small block V8, but I don't think that the block put under those heads is any different than the standard Chevy small block (Jim will likely know more than me about this). The only difference I can see in the block from the pre-'87 blocks is the use of a one-piece rear main seal and the valvetrain is set up for the OEM hydraulic roller lifters. There are conversion kits to use the old 2-piece rear main seal crank in the newer blocks, and there are also 3.75" stroke cranks available for the one-piece rear main block. I'm going to be building a hydraulic roller motor with the older type crank in it (because I want to continue to run the same 12" clutch that I've grown to like very much), so I will be using one of the conversion kits for the rear main seal.