A friend brought some parts to help me put together an engine, since I blew the small block in my '74 coupe. A Holley Street Avenger carb, an Edelbrock RPM Airgap intake, and a pair of Vortec heads fresh from the machine shop. These parts are new, none of them have been installed on an engine yet; he decided to go with an LS1.

I remember when the Vortecs came out 20 years ago, and had heard they were a great bargain, so I did some reading:
http://www.superchevy.com/how-to/97458/

My heads have had screw in studs and guide plates installed, so I can use standard rocker arms(I have some roller tip rockers from the blown engine) as well as re-drilled so I can use old style valve covers. Reading the article above, I see that with a few special tools, you can modify these heads at home for different valve springs and guides, to allow up to .550 lift cam. I am wondering if this was already done at the shop when the heads were rebuilt. Can I tell, without disassembling the heads and putting calipers on the valve guides? Maybe by measuring the valve spring O.D.?

Also, I need to pick a cam. My car is fully optioned, A/C, P/S, P/B, etc. so I figure it weighs 3500 or so. I have a four speed and 3.55 rear gears, and will be using header side exhaust. I love the sound of a lumpy cam, and they do turn heads on cruise night, but I want the car to perform as well. Don't care about gas mileage, and would prefer not to adjust valves on a solid lifter cam(never have owned one). Budget is tight so roller is out. I'm thinking low end torque is what I need for stop light to stop light fun, high RPM power probably won't do me much good. Won't see a lot of freeway time, ten mile runs to Galveston on nice days would be fairly common. Any help would be appreciated.

 

FYI - That intake may not work with the factory vortecs, you will want to do some research along those lines - those heads have a different intake bolt pattern. The Edelbrock 2116 will match up. I think Edelbrock might have an air gap that will fit vortecs, but I'm reasonably sure its not an RPM model. So just want to put that out there as a caution.

You could just mock the heads/cam up and measure all the clearances - you should do that anyway. It's possible they were machined to allow more lift.

When I had the vortecs, and considered going flat tappet, I had the Comp XE262 recommended to me - most folks I talked to thought that cam and head combination was a good fit for a driver, this was for a 79, automatic (700r4) with 3.55 gears. I ended up going with the vortecs and a small roller cam (don't recall exactly which one) with similar numbers - it was a good tight-running little 355.

 

have you tried the competition cams software downloadable from their site?

 

Actually they have the Edelbrock 7516, RPM Air-Gap for 1996 amd later Vortec cast iron heads. I better check and be sure that is the intake I have. It is still in the box.
https://www.summitracing.com/parts/edl-7516

I'll check out that software, but I'd like to hear some real-world experience.

 

[QUOTE=Richard Daugird;1593587381]Actually they have the Edelbrock 7516, RPM Air-Gap for 1996 amd later Vortec cast iron heads. I better check and be sure that is the intake I have. It is still in the box.
QUOTE]

Cool - been a few years since I had that setup, so not surprised there is something else out there.

 

Well I'm screwed. Still have the stock 1.235 O.D. springs, which limits me to a .450 lift cam. Is there any cam that will make decent power with that small of lift?

 

This is an easy fix.
Get yourself one of these guide cutters and the matching arbor that slips into the valve guide and cut the guide boss down yourself using a drill.
I did this, and now sport .544 lift on my vortecs.
https://www.summitracing.com/int/parts/cca-4726

 

A machine shop shouldn't charge too much to cut down the guides. When you buy your cam, get the springs that go with it and take them to the machine shop to get the guides cut down and the springs installed at the proper height.

 

Unless you feel you are competent to do the work.

 

I have Vortec heads with the spring pockets enlarged and the guide bosses cut down, relatively cheap machine work. I have a .550 lift roller cam now but I originally had a Comp XE 262 flat tappet. That is a great cam for bottom end power.
I also have an Edelbrock RPM Air Gap manifold. They only make that as a square bore, but I am using an adapter to run a Qjet on it.

 

We checked the valve lift on the heads, and sure enough they bottomed out around .440, so I think I will get the tools and enlarge the spring pockets, and cut down the guide bosses. Anyone have the tools I can borrow?

 

I had planned to do the same things, I started researching it and found alot of people saying that when you machine the valve spring seat it can lead to cracks. Anyone else have experience with this?

 

Post in the regional secton maybe someone has them
The cutters from Summit are real cheap.

Maybe Ill buy them from ya when youre done.

 

It's about $150 for the cutters. I have read countless articles/forum posts where folks have done this for years, haven't heard anything about cracks. Doesn't mean it can't happen.

 

I posted an ad over there. If I do buy them, I'll let you know when I'm done with them.

 

For spring pockets or just guides?

Plan on hopefully in about 6 mos or so (if I cant save my job) doing quite a bit of head work probably use them a lot. Cheaper is better right now

 

I'm doing both.

 

For what it's worth, I have the Summit brand Vortec heads and they were a great upgrade for me. These came already machined for larger lift - up to .520. These are $339 each. https://www.summitracing.com/parts/sum-151124 I don't know if this helps or not. I got the Edelbrock 2116 Performer vortec-compatible intake and have a Comp XE286 cam.

 

I'm going with the Vortecs because I got a complete new top end for next to nothing, but cheap/free is no good if it isn't the right combination for my needs.

 

Wondering if selling your heads and spending a little more now on the ones from Summit might be better for you. Bonus is they are brand new no valve job to so , springs, guides surfacing or anything else. Just a thought.