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Opinions needed. I bought a new set of Vortecs for my L48 from my local "head rebuilder"
My cam has .454 lift. He says stock Vortecs will handle this. Some articles I've read say yes , some no. They all can't be right ! Anyone running stock Vortecs with this lift ? Should I take the heads back and tell him to set it up for .500 lift ?
I hate spending $ if I don't need to - who doesn't ?
Call a different machine shop and see if they can be checked for lift. If they can't, have them do the work. If yes, you may owe them $20 for their time and you're all good.
Have the shop pop off the retainer and spring. Reassemble without the spring. Measure the clearance from the bottom of the retainer (at the valve stem) and the top of the valve guide/seal. You have to have enough clearance for the cam lift at that point. MUCH easier to check this before you assemble.
Opinions needed. I bought a new set of Vortecs for my L48 from my local "head rebuilder" My cam has .454 lift. He says stock Vortecs will handle this. Some articles I've read say yes , some no. They all can't be right ! Anyone running stock Vortecs with this lift ? Should I take the heads back and tell him to set it up for .500 lift ?
I hate spending $ if I don't need to - who doesn't ?
12558060 - GM Performance Parts Small Block Chevy Cast Iron Vortec Cylinder Head - Complete 12558060
64cc Chamber, 170cc Intake Runner, 1.94 Intake, 1.50" Exhaust - Complete - For Use With Cam's Up To .480" Lift
A friend of mine, Forum-member 80crabvette, recently got vortecs from SDP, but only after I encouraged him to get the upgraded heads, with valve-springs good for .525"-lift.
The '07 GMPP catalog, for whatever that is worth, states that standard vortec heads under the above part-number, are good for .475"-lift.
JEGS says the same thing - .475. I know the 330 HO GMPP crate engine has a dual pattern cam in it with over .450 lift on the exhaust side. I would tend to follow GM's site as you noted.
The furstrating part is the variance on the lift numbers depending upon who's site you read.