Question 1. I was wondering if you could place the rotating assembly of a LS into the block of a GSR or would there be alot of machine work to get it to fit. I know the B series engines are interchangeable and everyting but just wondering. And I know that for the money I should just buy a GSR but I want to build something different.
Question 2. When building a LS/VTEC how much can be shaved off the block and head b4 clearance becomes an issue. I'm gonna use CTR pistons if that helps. Also I heard that if too much material is shaved from the head and block that base timing is affected, is this true?

Thanks for anyone who can help me with these few problems.