Welcome to CHR from a UofA Razorback now in Kansas. You pointed out that your block is already 0.040 over, so it's clear you're talking nominal numbers as opposed to specifics on your cubic inches, which is perfectly OK - nothing to get hung up on. With the TH350 you're looking at something in the 500HP range at the crank to yield 400RWHP (~20% losses through the gears), which is a pretty healthy build. Several guys on here can get into the specifics of a SBC build with you. If Tech (TechInspector1) had his super computer out of storage he's got the Dynosim software to run tons of variables to get you where you want to be, and the knowledge to plug & play it right. In fact he can probably get you there from memory, and explain the "why's" along with the "how's". Good luck on your build.