I recently bought a lt4 camshaft and I am purchasing a set of vortec heads within the week. I would like to run 1.6 rockers and get the advertised .480'' exhaust lift from the lt4 camshaft. Would I be able to achieve this with a spring change? If so what springs would you recommend?

Would I have problems with studs coming out at .480'' lift?

 

Wouldn't recommend it, but I am getting over .490 lift with the heads remaining stock. I just go easy and don't race it that much. I do get on it hard when the time beckons however.

You need better springs, and while you are at it, might as well replace the seals and get a 3 or 5 angle valve job too.

 

I would recommend upgraded springs with screw in studs and new seal...no valve job otherwise you start screwing with a perfect head.

Set the seat pressure as low as possible...you won't need more than that for .480 lift

 

SDPC sells Vortecs already prepped for .480" lift.

If you get stock heads, upgrade the springs as mentioned. Make sure there is at least .040" more clearance between the guide/seal and retainer than you have lift.

You'll need self-aligning rockers unless you have guide plates installed.

 

just a thought.........i bought a set new vortec heads from jegs and the lift from them would only accept up to a .470 lift....you might want to check them for anything over that.....and as they previously said i would make sure to change the pressed in rocker studs to screw ones......

 

I have a set of used Vortecs. I measured the retainer-to-seal clearance.

With the stock seals I measured .540". So allowing the .040" clearance that five7kid recommends, that still leaves .500".

I don't know where Jeg's, CHP, and all those other places are coming up with .465" and .470" being the max.

Maybe they're talking about the stock springs???

 

The heads Im getting could already have better springs I don't know. The motor had the vortec heads and the lt4 camshaft I have in it. I'm gonna do springs and seals at least. I don't know about the screw in studs just yet.

Are stock rockers self- aligning? Im not sure about valvetrain **** really.

 

Car craft stuck a set of these springs on Vortec heads to achieve up to 550 lift without any other changes to the heads.
http://www.jegs.com/cgi-bin/ncommerc...63&prmenbr=361
http://compcams.com/whatsnew/NewsDet...ID=-1373872784

 

They put ls1 springs in it? What diameter are they?

 

im pretty sure those are too big, 1.445" diamater

 

Too big, I don't know. Just read the article. They put those new springs on vortec heads and the results were good. 550 lift and lighter other 'performance' springs.