will the vortec heads bolt up without problems to my stock LO3? I know that the intake bolt pattern is different so i will fix that. Also can I use the stock self-aligning rockers from my 305 heads on the vortecs? who else around here is running vortecs?

 

no. The Vortec 350, L31, heads would need to be milled to keep your compression up. good luck yes couple people

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-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

To be installed eventually far far far into the future: Yours if the price is right and I don't have to ship :
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz

[This message has been edited by Tas (edited July 15, 2001).]

 

I know that the vortec head has a 64cc chamber size so it will bring down my comp ratio b/c stock is 58cc but I am going to put new high comp pistons in. As for the bolt pattern, the machine shop can fix that right? because they offer vortec heads with the '86 previous bolt pattern. All i wanted to know was if the vortec heads would work alright and fit fine

 

iroc22, to answer your question about using your stock intake, even after drilling and taping new bolt holes for the tbi intake you will still have mismatched intake ports. You will have at least 1/16" gap from the top of the intake to the top of the port you are trying to cover. It would be much better to buy a performer intake and add a tbi adapter plate. The performer will better compliment the heads over the stock intake and much less of a hassle too.

And to answer your last question, yes they will bolt on just fine as long as you use a 305 head gasket.

Steve

[This message has been edited by steve8586iroc (edited July 15, 2001).]

 

what would be a better intake to buy the performer 1,500rpms-6000 or the victor junior vortec intake 3,500-8000rpms
which would be a better choice
for a 305?-
for a 350?-
becuse the power range starts at 3,500 would i have like no power from 0-3500rpms(would i need a stall converter) thanx

 

thanks steve8586iroc, i will probably just take your advice and get a peformer intake so there is less hassle. Who makes a TBI to carb adapter? i heard holley makes one

 

anybody-which intake?

 

Victor Jr. would probably be a bit much for all but a pretty wild 350+ cid engine, I wouldn't even consider it on a 305.

-Mark W.
'88 SC Camaro w/ 305 TBI

 

the reason why im thinking about victor jrs is because its gonna be for my worked 355

 

I think the stock Vortec heads run outta breath above 5500rpms. If you fully port them and go with 2.02/1.6 valves, then they may go a little higher. I've also read that the Vortecs are kinda un-responsive to pocket porting. They already flow great because of the swirl from the runner/chamber design. Unless you hog them out quite a bit, you won't help their flow much.

Go to Barnes & Noble and look for "Chevy Small Blocks"; by David Vizard; published by CARTECH. Read the results for yourself while your there. He shows how to get the most outta these heads, but he also states that it'll only help up to .5" lift. Above that, the heads choke. At least that's the way I understand him.

Hope this helps,
AJ

 

thanx yea i think ill stay with the performer intake instead

 

yeah the vortec heads might not run that well past 5500 rpm, but my car sees the street the most and i won't go too often past 5500 on the street. I just figured these were good cheap heads. Later on maybe I will upgrade with some better heads. Thanks for the input.

 

yeah the vortec heads might not run that well past 5500 rpm, but my car sees the street the most and i won't go too often past 5500 on the street. I just figured these were good cheap heads. Later on maybe I will upgrade with some better heads. I'll take your advice and go read that book at barnes and noble. Thanks for the input.

 

Oh, I hope you didn't (or anyone else) take that the wrong way. Vortec heads are awesome!!!! They're exactly what I want. I was just trying to elaborate on the intake manifold question. The Victor Jr. would just seem like it would be too much for those heads. 3500 rpms is just about where the peak torque is on Vortecs. That intake would just make a crappie street car with those heads. Das all.

It's just hard to improve upon perfection. The Vortec heads are perfection, for there intended design. You just gotta remember that these heads were designed from using the LT1 casting, but they were intended for trucks.

I just love how GM hasn't jacked the price to kingdom come. 'Cause you know damn well they could if they wanted to.

Another suggestion, go with the Performer RPM. CHP magazine used that intake with the Vortecs, and it worked great. Gave a little more HP in the 4500-5500rpm range and didn't loose any torque down low.

 

AJ_92RS, what does the book, or you, think of the Corvette L98 Aluminum head? I heard that they are pretty responsive to some simple porting and because they are aluminum, they can take high compression

 

oh and are the L98 alum heads the same bolt pattern as the TBI intake?

 

The aluminum L98 Vette heads have the older pre-87 carbeurated intake bolt pattern. The TBI intake does not. I've got some pictures and flow numbers on my website for the L98 heads...you should go check 'em out.

-Mark W.
'88 SC Camaro w/ 305 TBI

 

The charts in the book favor pocket porting on those heads. The graph used does not give specific #s, but it shows the stock heads to flow around 190cfm @.5" lift, and around 230cfm after pocket porting on the intake side. 155cfm/180cfm for&aft on the exhaust. Both are at 28 in. H2O. of vacuum. That and they're 22lbs/ea. as opposed to 47lbs/ea. for iron heads. Now these flow #s are my own guesstimates from reading the graph. I could be 1-5 cfm off.

As for the intake question, I dunno. You'd be better off asking that in the TPI board. Or perhaps someone else on here will know.

TTFN
AJ

P.S. He also said that these heads can't be milled more than .02" because of the thin deck (but at 58cc chambers, why would you want to mill them that much?). So be cautious of used ones.

 

intake manifolds are easily modified fit whatever GenI heads. Pre or post '87.

 

thanks man you've been helpful. Now I just have to make a decision.

 

http://www.sallee-chevrolet.com/Chev...ortec_TBI.html
Problems solved. Just make sure you don't use a 2" TB unit. You shouldn't need or want a larger TB unit unless you're installing the heads on a 350+ cube engine.

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, Jon (350 TBI!)
91 Red My website