Robbie,

This was on a 240Z that I built just prior to building the McLaren replica. I had a Windsor block, and chose to use it because my other SBF ancillary parts (heads, headers, pumps, and a few other things) interchange within the Windsor family. The Cleveland is a little different.

In regards to the LS2 motor in the Manta? The LS motor design is probably the best designed, affordable engine I have ever seen. It's light-weight, nearly bullet-proof (you wouldn't believe what it has survived), and has an incredible aftermarket support structure. Plus, it only takes a relatively small amount of money to get 500 HP. You might want to consider that in your options as well.