I am formulating my game plan for my 350 and it seems (so far) that the Vortec heads are the way I will probably go. Can any of you tell me what you are running at the track along with what your combo is? I am thinking about the following: Vortec heads, somewhere around 9.0:1 compression, CC Carb, Edelbrock intake, 262 or 268 Xtreme Energy cam (specs say that the 268 has too much lift for the heads), headers, 3.23 or 3.42 posi, rebuilt 700R4 (don't know what stall to use on this with it being a street car), and the later on possibly nitrous. Would this be a 13 sec combo without nitrous?

Thanks,
Mark

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1986 IROC LG4 "Bone Stock" (for now)

 

It will easily run 13's with the parts you've planed. Replace the stock valve springs you get on the vortecs, with crane, comp or isky stock diameter, high perf springs. You can reuse the retainers locks and seals. Have a machine shop shorten the tops of the valve guides .200" before installation. The stock truck vortec springs do not have enough pressure for performance work. Make thr CR 9.8 to 10.0 and use a 2200 to 2800 converter. Use 3.73 or 4.10 gears. Plan on getting some hi traction tires like BFG drag radials, if you want to cut some quick ET's.. Good Luck.

[This message has been edited by F-BIRD'88 (edited November 14, 2001).]

 

I am using the Vortecs. All the engine numbers are in my sig. I havn't had this at the track yet, but it will beat my friends 2000 Z-28. Traction is a big problem. I am running stock tires to try and save the 5spd. I used +.050 valve locks and this got me .580 clearance for the spring. This does leave little room for self aligning rocker arms. I am using stock diameter springs that will handle .600 lift. I love this engine. I just need to find a way to harness the power without breaking the trans.



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Joshua Johnston
1991 Z-28
350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust, Dynomax Bullet Mufflers, T&R Motorsports custom air intake, Bald tires

 

I use these heads on my 83. I use xe 268 cam andair gap intake. I have 3.73's and posi. The converter I use is a "Neal Chance Racing" converter that is about 3,000. The bottom end is a 350 with 10.9:1 pistons. Heddman headers and Flowmaster muffler. Also the car has a 700r4 and the carb is a 750 Holley.

The car is very quick for a street car. Although I don't have numbers I can say that it will smoke my 94 Z-28 that has ran a best of 13.82 in the 1/4.

I had regular tires on the 83 and had to switch to BFG drag radials. I am hoping for 12.90's with this car. I think that there is someone on this board that has ran a 13.00 with 3.42's and 1.5 rockers with this setup. I use 1.6 rollers.

 

You can get new Vortecs premodded to handle up to around .550" lift from Scoggin Dickey for like $550 or thereabouts for the pair. That's not too bad...

I'm running the XE262 on the stock setup myself with no problems.

GM gives the Vortecs a pretty low max-lift rating, yet according to the numbers I've got they are running like .460/.481 lift on the Ramjet 350 crate motor straight from the factory (They put 1.6s with the regular 330hp Vortec crate motor's cam)... There are several people I've seen around the net running the 268 on the stock Vortecs for what it's worth.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited November 15, 2001).]

 

I cant remember which one, but one of the car mags. ran the vortecs with the x/e 268 and it came out to like 375 horsepower.

 

Chevy High Performance. It was their gm goodwrench buildup.

 

I love my vortec heads. I put them on right out of the box. Doing the gears this weekend, 3.73 www.thirdgen.org/rides/index.tgo?action=view&rideid=7480



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1988 Camaro Sport Coupe: Orignally: 305 TBI 700r4
Now: 1974 355CI, 2bolt, Badger Flat Head Pistons w/ valve relief, Melling high performance street cam, GM Cast Vortec Heads, Edelbrock RPM Air Gap Intake, Edelbrock 600cfm w/ electric choke, GM HEI w/ vacuum advance, Weiand Low Profile Air Cleaner, Mallory 5 port Fuel Pressure Regulator, Mr. Gasket Throttle Cable Bracket, Corvette Shift Servo, 16" IROC Wheels, Every thing else is STOCK
Best Times:60ft 2.26 1/8th 9.68 @ 73.63 Soon: 3.73 or 3.42, Gears, Hoosier Q/T
https://www.thirdgen.org/rides/index.tgo?action=view&rideid=7480

 

Was over at a buddies yesterday and he happened to have a set of vortecs torn down for porting. Measured the clearance between the stock retainer and seal. I got .480"
Not much room to spare. The stock springs had
like 70lbs seat pressure at stock installed height. When I prepped my own heads before
I checked them and there was not much clearance on them either. Once these details are taken care of, they make a pretty beauti head.

 

Thanks for all of the input! Has anybody run their car with a combo like this?

Mark

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1986 IROC LG4 "Bone Stock" (for now)

 

Yes

 

Actually, what I should have said is, has anybody raced this combo at the track?

Mark

 

Yes I have....

 

F-BIRD'88,
Did you get into the 13's? That is my goal. If you don't wish to give specifics, was it in the range of the new Camaro's times? Also, what octane gas do you have to use? Thanks for your help!

Mark

[This message has been edited by wiggy'sIROC (edited November 19, 2001).]

 

My best times so far are
13.44 @104.58 mph

I use 94 octane Sunoco exclusively
my compression ratio is 10.03:1
Not only does this pump gas eliminate
knock but also makes slightly more power
than non-oxygenated gas. So it's worth the
few extra pennies at the pump.

 

F-BIRD'88,
That is what I am looking for out of my car. I don't get that kind of gas here. Would 92 octane do it? Thanks for all of your help between this and my other post about factory heads!

Mark

 

the 268 or 262 cams will work nice. Why only 9.0:1 CR? are u planning on using nitrous? you could easily get 9.5:1 or even 10:1 and be very streetable on premium gas. I'll tell my friend to look at this thread, he posts as Pony Killer on here, he's building a very nice carbed vortec headed motor, no times yet cause his tranny isn't done but he built this thing himself...he'll give u the low down on the parts he used

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*89 Trans Am GTA
*Moderator at www.transamgta.com

To hell with the GM vs Ford war. We must unite, as brothers to fight the plague that is overtaking the world...RICE

Tony

 

If you built for 9.5:1 cr you'd be sure to run fine on 92 octane gas and make lots of power.

 

I've got the Vortec, Carb combo. Haven't fired it yet though, as Fly said.. waitin on the trans.
I'm Running 10.5-1 compression, Vortecs with a Valve job, and bowl work, Performer RPM intake, comp XE 274 Hyd, cam.Crane race gold rockers,and a 780 holley, 3000-3200 converter, 3.73 gears, Suspension goodies.

Looking for mid-low 12's