I just bought a 6-71 blower for my chevelle and I want to know if the pulleys that came with it will be ok for the bbc I'm building, the crank pulley has 60 teeth on it the blower pulley has 50 teeth on it and the belt has 1440 8m 85 on it. Any idea what kind of boost it will put out with these pulleys?

A 50 tooth pulley on top and 60 on bottom gives you 20% overdrive. That is a lot of overdrive for a street 6-71. Must have been on a big, big block. By the way, the bottom and top pulleys are interchangeable. Reversing them gives you 16.7% underdrive.

To attempt a rough estimate of boost you have to post your blower size (a BDS 6-71 street blower is a bit smaller than the standard 411ci 6-71 blower.. there are different size 6-71's also - big and small bore), blower condition (a tight new blower makes more boost) and whether it is teflon stripped or not, and of course engine size.

However, cam profile, head runner size and other factors will all change the boost you will make for a given overdrive/ underdrive, so it would only be a rough estimate.

Well the blower was originally of an alcohol injected dragster with a BBC, I'm just going to put an adapter plate on it and run some Holley blower carbs. The blower is Teflon striped, I have a 30 over 454 that it’s going on, the heads have 223- int and 188 ex valves with 113 cc combustion chambers. I have not got the camshaft or anything else for it yet, I'm most likely going with a forged eagle rotating assm, with probably around 7.5.1 compression ratio but that is not for sure yet as I am still trying to figure the best way to build this engine and still run as much boost as safely as I can.

Oh and I’m going to be running a solid roller cam in it, the heads where originally of a blown alcohol altered, the springs on it can support up to a 730 lift cam. My heads are oval port and the blower intake is rectangular port, the guy I got the blower from said for the street I can just put a rectangular port gaskets on it and it will work fine, Is this ok or should I go get the right intake for it?