Quote Originally Posted by Fast-Tech™ View Post
Not the expert here by no means, but I'm not sure I would ever choose a B20b for a boost motor. Just of how thin the cylinder walls are. And if I did run boost on a B20, it deff wouldn't be no more than 8 to 10lbs of boost. If you want boost, just do a LS/V or LS and if you want a N/A motor and B20 would be a great candiate. I plan to run a B20b block with a GSR head in my DA9. But I'm a N/A type of guy.
LS/V and B20 aren't that much different, both motors have weak ass rods so I don't see why you say ls/v would be better. You are however correct on the b20 cylinder walls. On stock internals, you should be fine anywhere between 8-10psi TUNED, and not revving the piss out of it. Both motors b18a/b and b20b have low compression so they are both suitable for boost.

N/A wise, they are the same minus displacement. A ls/v NA is pretty much the same as b20/v NA on stock internals. Both need more compression for NA apps. A p72 head and a 2-layer headgasket will help but not by much, vteckidd has a compression ratio sticky in this forum.

BTW, to the O.P. whichever direction you choose, spend the extra $100 or so for ARP rod bolts and head bolts just for a piece of mind.