Thanks for the good info fellas.... I think I will stay with what I have now and get the carb dialed in. I bought it off ebay and put a rebuild kit in it as the power valve was blown. It cam off a chevy 396 and it obviously did not work right. Now it works just about perfectly on my 390. I was the one who decided to put the light spring in for the vacuum secondaries. From a roll it has the response of a DP but from a dead stop I think it opens up all 4 barrels too soon and it is killing my vacuum. It does not bog at all, it just does not start pulling good until over 3,000 then it gets with the program big time. If I can leave the line on just the primaries will this give me more torque???? TBF

Pic is the KB forged pistons, quench pad clearance is .005 with a .039 gasket total quench around .044. Runs perfect on 93 octane.