i have a 468 bbc with a solid roller (238/246 dur .622/.622 lift 110/108), weiand stealth dual plane, 9.5:1 comp, 18 deg initial and 38 total by about 3000 rpm for timing (no vaccum adv), holley double pumper, super comp 2" headers, x pipe with flowmasters, and 3.90:1 12 bolt. the holley was originally an 800 cfm, so it had a power valve on the prim and the sec side. i bought the proform 750 main body and put 72/84 jets with a 6.5 power valve in the primary and a plug in the secondary. i have about 10 hg of vaccum at idle with an auto trans. i recently discovered the p.v. was shot. i took it out and put a plug because i didnt have another power valve available. i jetted it to 80/84, but that was too rich, so it now sits at 76/80. that seems like low jetting for no p.v., but it actually seems to run good. my question is: do i really need the annoying power valve???? the plugs dont look as good as they did when i had the pv in, but they still look ok. i know theyre cheap, but the thin rubber diaphram seems to wear out. i have a pv protector in the baseplate, also, so i think the pv just got old. if a p.v. is recommended, should i put one in the sec side also?? thanks for any help.
nevermind. i did some messing around and it definantly runs better WITH a power valve! according to another source that i discovered, i put a 6.5 in the prim and a 5.5 in the sec side. i have 10 or 11 hg vaccum at idle and an 800 cfm double pumper. sound correct?? thanks.