Hey guys what is the max lift u can run on the vortec heads, i was thinking about getting some from summit but my cam has 480 lift and 230 duration at .50 would it work?? also if not around how much would a machine shop charge to grind the seats down for me?? thanks so much guys.

 

I'm pretty sure that they can take .460 lift stock. Scoggin Dickey sells upgraded vortecs for more lift for not much more money. Thats where I got mine.

 

ive heard 430 or so max for the stock ones off a truck, and the new summit catalog says .475 now, but said .450 or something last month... the scoggin dickey catalog says about the same (.450, but i dont remember right and dont want to get it out...)

BUT the new GM performance parts catalog says the gm vortec performance heads, part numer ending in 060 i think, can take .475 stock... so either way, .480 wont work unless you get the upgraded heads from scoggin dickey or gmpp makes an upgraded valvespring version too...

if you have already bought some vortec heads, you can buy a tool that will machine the 3 things you need machined at the same time for the bigger diameter valvesprings from crane cams i think... (i believe comp also makes a tool that will do some of the machine work)

or you could take them to a machine shop and pay a little more $$$

good choice on vortecs tho, theyre good heads, and for 500$ theyre a bargain cause the flow numbers are better than some aftermarket heads that cost 400$ more.... i just put a set on the 400 im puttin in my 83... (goodbye 305 )

 

.480 is the absolute max lift on those heads. Most buildups don't take them past .475 without machining them to take .520 or higher.

 

Pace Parts says .480 max lift with these heads. I wouldnt chance it tho. Look into maybe a .460 lift max just to be safe.

 

right around ..470-480 lift the bottom of the retainer starts to hit the top of the valve stem seal.

 

You need this, and this.

And the spring kit you want is here, #VSA 3

I know it says "No machining required", but that's not for Vortec heads.

 

factory springs won't work, or last at that lift, pull out studs will fail, valve guide clearance becomes and issue around .45. you need to check clearances, not just thrown a cam in the short block, or heads on a short block without checking that everything is instaleld correctly. shop here charges around 150 dollars to grind seats. i use to get it done before i started doing my own for 40 dollars if to took everything apart. spring seats cost me 2 dollars each to get enlarged. i mill my and install my own screw in studs so no idea on cost. valve guides would be cheap and easy to mill, but i do my own so no idea on cost.

 

well if i buy them i will just get the ones already done. anyways with the head si have in my sig do u think by putting on the vortecs i will kill the liuttle bit of gas milage that i get? I wasn;t sure on this cause they are still 1.94 heads. but i am guessing cause they flow so much better then will hurt it a bit. thanks for any input