Alright, heres what i got. I took out the tbi and rebuilt everything. Everything is new except for the block is from an 84 5.0 HO and I kept the the rods and the piston heads, I had them professionally cleaned though. I have added the centerbolt heads for the new camaros, an edelbrock performance rpm camshaft, performer intake, and the 600cfm carb. My buddy and I built the bottom half of the block with mechanics every step of the way. We are now having some problems, we are hearing a distinctive knock coming from near the #6 or #8 cyclinder. We dont know if its a rod or the rocker arms. We adjusted the rocker arms, it did make a difference. This is the first motor I have ever built. So here are my questions.

How much horsepower would you say I am looking at? We did pull most of the emissions.
If it is a rod, how much are those to fix typically at a mechanic shop?
Also I was reading some other things about the fuel pump and how they had it wired to a 3 plug something? Why would you have to do that? We just left the ecm in and found that the carb was getting fuel to it. The car sounds good except for the knock. Which could be a big problem. We have drove it just to test...did fine some basic tuning we will have to do of coarse.
So if you have any knowledge I would appreciate it very much.