Did GM make a non-vortec center bolt head?
 

Ok- I just got in a lengthy argument with an employee of a local performance part shop. I told him about how I modified my non-vortec intake to work with my 1.94/1.5 Vortec heads. He told me that the only difference was the bolt angles- and said there was nothing wrong with my set-up. After that, he proceeded to tell me that Vortec heads ONLY have 8 bolts, and all of the bolts are perpendicular(He showed me an intake like this, and its certainly not what mine looks like). I told him that I knew mine were vortec's
[I know they are vortecs. I assembled them myself- and my mechanic friend gave me a big lesson on what makes a vortec head a vortec head- showing me the differences. We honed the bowls in his shop].

He said that my heads arent vortec, and they are just an early Center-bolt style stock GM head.

Am I totally wrong here? Did I get ripped off when I bought my heads? This guy totally confused me!

The TBI heads had the center bolt valve covers, and have the 12 bolt intake and the 4 center bolt holes were angled differently.

Yep!

vortecs should only have 4 bolts per side on the intake not 6 like the older gm stuff. sounds like you got ripped off. and on the vortec heads all the bolts go straight down. heres some pictures i found to show the difference http://www.carcraft.com/techarticles/996/index2.html

Yes, GM made non-vortec center bolt valve cover heads, if that's what you mean. IIRC, Vortecs have a "sawtooth" stamping on the front of at least one head. Best to check the casting numbers and ask someone on here what you have.

ok... so what are my heads exactly? I'll go check the casting numbers tomorrow.

They are the 12 bolt kind, with the 4 center bolts angled perpendicularly.

I've seen listings on ebay for heads that look exactly line mine, that claim to be vortec. Is this a common mistake?


The truck moves like hell for such a mild cam. It does 15.6's very consistantly, even with the wrong intake(well apparently it *is* right)

Ugh..

So do the TPI heads.

your heads are just run of the mill stock centerbolt heads from 86 to 95 or so. they are generally thinner cast than older stuff and definately not optimal for performance stuff

In the past I've emailed sellers on eBay who had them deliberately listed incorrect and continue to do so. I've also warned a few bidders. Yeah, I know but screw eBay's BS policy, can't stand scammers. They always seem to sell as vortecs and they get positive feedback from the sucker that "wins." Go figure. That's why casting numbers are important to get.

It takes a lot of work to make a non vortec manifold work.The angle that the intake meets the head is completly different.Takes lots of welding and macchine work.When vortecs first came out there was not many performance intakes available.They had to be built.

.... Thank you guys for the help.

I'll get the casting numbers this afternoon. Is there a site that I can look them up on?

Thanks

www.mortec.com

There are a few others but the most common are 191 (305 58cc) & 193 (350 64cc) which are both TBI heads. Then the 081 (305 58cc) & 083 (350 64cc)TPI heads.

I just pulled the valve cover off the driver side(2-4-6-8 cyl's)

and I got the casting:

14102193


on mortec, it said:

14102193...87-up...305/350......1.94"/1.5" valves


Is this a TBI or a TPI head?

Yup, you have 350 64cc TBI swirl ports. They don't breathe in the upper rpm ranges. Good for low end though. You could grind the swirls out. But for what you do with your truck I would just swap them for actual vortecs or go aftermarket. Probably wouldn't bother with a set of TPI heads because they'll need some work too. Live and learn I guess. :(

wow. I really feel like a dumbass. I bought them from my "mechanic", who is a friend of mine. He has built some serious hot-rods in his time, but he's an older guy, and hes pretty "old-school". I honestly think he just asumed they were vortec heads because of the bowl design. I only payed him like 150 bucks a peice for them, and he helped me assemble them and put em on. I guess it was worth it just for the experiance, and im sure they flow a little better than the stock "L82" crate motor heads that were on it. I know he doesnt know much about new engine tech, but he sure has made my truck damn consistant. It can duplicate runs in the hundreth's on command. It just upsets me to know how much more power my truck *should* be making right now. I mean, it isnt a slouch, but I wouldnt mind it droppin the ET a little.


We are in the process of putting a motor for it together right now anyway. He had a short deck 427 block that we planned on building, but he decided against it because of part cost. He has a sbc 400 which has been freshly bored to .030, decked, and ready to go. We're going to put a set of AFR aluminum heads on it(2.02/1.80), and increase the stroke. Forged dished flat tops- something to the tune of 10.25 compression, and about 425-430 cubes. It'll still be a reliable street motor(it'll easilly run on 91 octane. And maybe even 89 with some timing taken out)

And the best part is, as long as I do all the work, he isnt charging me a dime for it. He has the parts laying around, and doesnt have any use for em. I just have to give him my motor to put in a car he's restoring as payment!

Thank you guys for the help!

just remember the actual "vortec" head didn`t come out until `96.alot of people assume that the `87 up heads,w/center bolt v/covers were vortecs.

Ok another question about the heads!
I was looking through that motec page and I found these two vortec casting numbers!

10239906...(year)96-up...350.........."Vortec 5700", "L31", 64cc chamber, 170cc intake port, 1.94"/1.5" valves

And

12558062...(year)98......350..........L31 Vortec, truck, 64cc chambers, 1.94/1.5, 170cc intake port

Whats the differance?

In my opnion, you did NOT get ripped off. You got a good deal on decent (non vortec) heads.

Jeez, had a post disappear in here. Anyway, were they worth close to $300 for a used set...no. Considering all that he's been doing for you, you really didn't get ripped off. You're still making out. If you're bracket racing you want to be consistant anyway.
Here's what you have in pic 1...
Vortec in pic 2...

Funky3821, no difference really, just actual casting number.

15.6 is good I doubt if a head swap to L31's would be worth your time and money. Just spray a 150-200 shot on it and replace the heads when they fail lol

They're a 30hp or so boost to any pre-vortec headed motor, thats worth the time and money to me.

The difference between the 906 and 062 castings is [drum roll] nothing! :D Some of the 062 castings had different seats installed for 3/4-1ton HD applications. Some claim that hurt flow, GM stated it didn't. I belive they don't flow any different myself.

I have seen complete "new" vortec from a couple of catalog companies for around $450

Do you people know about http://www.gmpartsdirect.com/

30 HP is a good gain just by switching heads, but I wouldn't bother with a head swap unless I could bolt on 50 HP, unless something is wrong with the cylinder heads on the truck and you just looking to replace the cylinder heads with some factory cast heads.

@ chevy72blue
I know we got into a brow beating contest before, and I would like to apologise. Here is a link that can better explain the vortec head which is the L31 head.

One thing that I would like to clarify the "vortec" that has been rated so well is the L31 design that first apeared in the 98 trucks. But GM calls just about all their motors after 97 "vortecs" 4,5, 6,and 8 cyls use the Vortec name. Thats why you see a lot of people selling vortec heads..... but it is not the L31 vortec head thats been a good performer. Someone may be selling you a "vortec" head with out any intended malice, its our own fault we made that Vortec name stick, when it can mean alot of diffrent models.

http://www.sallee-chevrolet.com/Cyli...ds/Vortec.html