I've already searched around, and found the difference of the non D16y8 blocks, as far as them lubricating more effectively... But there were also some rumors of better compression using a different head? I recently pulled an engine in awesome condition from Pick-A-Part, only 103k on it. I plan on swapping almost all moving internals out for performance parts in a big rebuild and boost project, but I'll post my plans with that later. My question is, since It's ridiculously hard for me to find a relatively clean, non rusted/cracked block that ISN'T a Y8... is it worth it to drop 400-1200 more on a refurbished z6/a1/y7/d15 block? I don't really want money to be the end all here, but I already have a really nice D16Y8... I'm just wondering if the cash cut is worth a little better lube, and MAYBE a small bit of compression. Keeping in mind I'm not going for a 10 second honda or anything, I want to boost 10-18 and not looking for more than 300whp in the long run, I think even that may be overkill since I don't plan on drag with it, only hard driving. Facts and opinions would be awesome.