The bore depends on if you want to runs sleeves or not. All blocks can be bored to the same size. Heads are pretty much the same. You're going to rework them anyway. You can get 56 cubes out of any of them.
I'd prefer not to re-sleeve...for now. When you say all of them can be bored to same size, is that with stock sleeves? Or, do the smaller bores need re-sleeved?
What kind of interchangability is there between horizontal and vertical? Heads? Cranks?
Thanks for the replies, it's very helpful. I have a line on a couple CV23's I'm gonna pick up and do some experimenting.
As for major part suppliers, I know about these guys. Are there any others I should know about?
Vogel Manufacturing
MWSC
Lakota Racing
Zach Kerber Machine