I'm buying a set of vortec heads off an engine that was seized. I believe they are 906's.

I want to send them to a machine shop with me supplying the parts.

What springs, valves, screw in studs, retainers, such should i buy that would upgrade it to handle .500 lift?

 

You better ask for a quote for all parts/labor before you let them do it. With all that you mentioned, you will be coming close to buying a set of aftermarket heads ready to bolt on and run.

If .500 lift is all you are looking for, I would consider having the shop check the heads and do a valve job. Then I would probably just get the Alex spring/retainer kit. Of course that all depends on what you are wanting out of this motor and what your budget is.

 

Kinda aiming for 350-360 hp.

Right now it's at 270hp with tbi heads and absolutely is zero fun since I'm having to shift below 4200 rpms.

 

Do you currently have the self aligning rockers? The push rod hole in the Vortec head isn't designed to guide the pushrod. If you have the rockers then you can skip the guide plates and save a little money.
For what it's worth, a Comp 26918 spring and associated retainers and keepers will drop in with no machining and provide capabilty the lift you're looking for. Your limitation then is the press in studs.


This is exactly the reason I chose not to invest any more money in my old Vortecs. They've been machined for guide plates and screw-in studs (I use a traditional style rocker arm albeit a Pro Magnum), I'm using the 26918 spring assembly too but when they started to get old and new guides and a valve job were needed, I put the cash towards a set of RHS Vortecs. Better head, better casting, bigger valves, more flow and all the upgrades. Plus they're new.

 

Well, hopefully assuming you got the heads pretty cheap. Let the machine shop check them for cracks, clean them up, and do a basic valve job.

Then either run a spring kit like the Alex's or the 26918 mentioned above. I went LS6 springs with different retainers. (I have a thread on that somewhere on here).

Combined with a decent cam and you should get what you are looking for. Just dont sink too much money into stock heads. The factory vortecs are the best factory head, IF you can use them cheap enough.

 

Sent OP a PM.

 

I'll keep that offer in mind man.

 

100$ for both heads. Not bad at all, i think anyways. Friend drives an import now and doesn't need them.

 

Thats not bad at all.

 

It'll be interesting to see how much your machine shop charges you for the valve job and upgrades. Things like springs/spring kits, guide plates and studs are known amounts but the labour portion can change from shop to shop.
For what it's worth I've attached a copy of my invoice from 2007.
Something to consider is that while I did upgrade these heads, I enjoyed them for several seasons in stock form. The cam I ran was an older 268 grind with .454" lift and I had no trouble with it. The springs did a fine job as they were fresh and I kept the rpms below 6000. It wasn't until I went with a 1.6 ratio rocker arm that I had the heads reworked. Keep in mind the price in the invoice does not include new guides as mine were still considered to be servicable.

 

I had a set of 906 heads cleaned up, valve job, new springs/etc.
Price was as follows:
3 Angle Valve Job - $300
Remove rocker arm studs, drill & tap 7/16” screw in studs - $180
16 New valve stem seals - $21.84
Set up springs 125 seat load at 1.800” installed height - $150
Springs Shim - $5

I went with:
Comp Cams Street/Strip Beehive Valve Springs ($206.79):
Comp Cams Steel 7* Vale Spring Retainers ($53.98):
Comp Cams Machined Steel Locks ($23.19):
Mr. Gasket Rocker Arm Studs ($35.95)


That's about $1,000 not including an initial purchase for the heads. You are better off buying an aftermarket set of heads in that price range (Dart Platinum).

 

Hmm, how much lift could i get away with before the press in studs rip out? Any idea?

 

It's more a function of the spring pressures involved. The stock springs and the press-in studs get along fine. As far as lift goes, you're limited to about .460" lift and from my experience and from what I've heard, that doesn't seem to be a problem for the press-in studs either.
Step up to the 26918 spring or equivalent and the advice is to upgrade to a screw-in stud.

 

While the 918's may work the spring pressure will be through the roof because vortec heads with stock vavles do not have the correct installed height for those springs.

 

True enough.
A Vortec uses a 1.7" installed height as a reference whereas the 26918 specs a 1.8" height. However if used with a .050" offset lock (Crane 99095) there's no problem that I've found (at least not with my retired Vortecs and a roller cam). With the 26918s 372 lbs/in spring rate, the reduced installed height (1.750") adds 18 lbs of pressure.

 

If your going to have a cam with .500 lift you have to have the valve guides machined down so the retainers don't hit the top of the guide.

 

Welcome to the forum.
If a small spring like the Comp Beehive (26918 or 26915) or a comparable LS spring, the small retainer that's used provides the additional clearence at the top of the guide. It's one of those no machining upgrades. This is the setup on my Vortecs.
Keep in mind, as 1986Z28OWNER states, that the installed height spec for the Vortec spring (1.7") is less than most aftermarket springs. You would need to use an offset valve lock to get closer to the Beehive installed height of 1.8".
If you're really going to go at a set of Vortecs and install larger valves (and all the porting that goes with it) then a .100" longer valve can be used. This may eliminate the need for the offset lock.

 

Did research and decided on a comp xe268 cam.