by spencerforhire » Sun May 18, 2014 7:27 am
There's so many variables that in the end you'll have to do the "lump of clay" test to make sure. Not just the valve diameter variable, but camshaft lift, duration & centerline, deck height, head gasket thickness and even the head(my AFR 227's and others have non-OEM valve spacing) itself can effect piston to valve clearance. Just went through this process myself; I had intended to run 1.6:1 rockers on at least the intakes but ended up downgrading to 1.52:1 all the way around just to keep the clearance safe, especially on the exhaust. I could have advanced the cam a couple of degrees, but it wasn't exactly where I wanted it to begin with and had already made compromises in that area.
The "fleet"-
72 Vega HB Drag Car -383/'Glide/9"(9.35@146.19)(5.94@117.28 1/8th)
77 Vega Estate wagon- project(someday)will have TPI305/T-5, S-10 spindles/axles
76 Vega GT- 400/4spd/9" retired from active duty(rusty)
06 Silverado 2WD ex.cab daily
03 Silverado 2WD ex.cab (retired)
06 Haulin' 20ft enclosed car transporter
06 GMC Canyon Shop truck
07 Colorado project( 5.3 4L60e swap)
99 Saturn SL1- wife's car
01 Saturn SC2- son's project
07 Saturn Ion Redline project
and 4 more Saturn "parts cars"
Note- the very act of listing all of these has made me realize I have some kind of problem.....
Visit http://www.spencerforhire.ca