Hey guys, I was looking at buying a set of vortec heads fromn summit for my car and I was wondering that after I got the guides machined to take a high lift cam for $35 bucks, What can I do with the springs?? My cam has .480 lift on it. Now could I use the stock springs that come on these heads and not float them or what?? I shift at liek 5500 at the most if it makes a difference. Thanks

 

if you can buy them bare would be the best way to go. while you're machining the guides down mill off some of the stud boss and tap them for screw in studs and get the spring seats opened up for larger springs. trash the factory springs if you get heads with them along with the factory rotator and retainers.

 

press in studs will be fine with a 480 lify cam, but will the springs work? Cause if I have to get all that machineing done and get springs it woudl probably be cheaper to just buy a nice set of darts

 

The stock springs on Vortec heads are junk. They're stock truck springs, meant to provide longevity when used with a lazy truck cam in an engine that never gets its oil changed. They will not be able to control the valve motion produced by any cam with anything resembling a performance profile.

Get the right springs for your cam.

 

Y not just buy an upgraded Vortec head with the mods done already like from Scoggin Dickey

Or a set of Protopline "906" aftermarket vortecs.

 

Actually you have a good head on your car now.

They are a good head but flow is kind of modest to say the least out of the box.
But you can fix that. You would need to remove them, port them, install larger 2.02x 1.60 valves, unshroud the chambers, cc the chambers and have them milled to get your true compression ratio up to 10:1.

Those heads are typically 67+cc's the compression ratio is too low.

You may even have the 76cc versions on there.
that would explain why your not happy with it.

You could do all this for far less than new heads.

 

the thing is I can't be without a car for that long. If I got new heads I coudl change them on a saturday niught and have it done by mid day sunday. But say I do go the route of getting all that stuff done. What do machine shops usually charge to put in new valve guides, and open the valve size up to take a 2.02/1.60 valve combonation? Oh yea and does anyone know if there are numbers on my heads to check and see if I have 67 or77cc chambers? thanksfor all your help guys.

 

Surely you can ween yourself from your car for a few days. Find a qualified automotive machine shop that can port heads and get a quote and a time estimate.

Everthing you do in a rush will cause you to have to bypass or overlook details like ccing the heads,
(wether they are new or your well tweaked S/R heads)
measureing piston deck height and getting the right headgasket to "blueprint" the cr up into the 10:1 ballpark.

You're probabily at the 8.9:1 area now. Could be less.


The valve guides are likely ok on your heads unless its smoking.
Doesn't take long to street port a set of heads, install new valves with a competition valve job and throw 'em back together.

Remove a valve cover and get all the numbers off the heads. Both cast and stamped on the head.
Then you can ID them with the info off the World Products internet site. there is a ton of tech info there.

The published CC specs are a nominal figure. They are usually even bigger.

Its all about details.