[Tpower66]

Have a stock 66 gto tripower 389 4speed 3.36 posi 093 heads and 068 cam. Will a head change get me from 15 to low/mid 13s. If so which heads---if not what is your advice.

[mchell]

did what you are trying to do long ago....

just heads???......be a stretch, unless you're willing to up the compression(waaaaaaaay up).......realistically, you're gonna need heads, cam, exhaust and some gear to achieve your goal with moderate compression.....as well as some good tune....or get some cubes

[goatless]

Do you want to keep it looking stock?

Do a little porting on the 093s, bigger cam and either open up the log manifolds (like this-
http://forums.maxperformanceinc.com/...d.php?t=630943 ) or install RA manifolds. A little more gear wouldn't hurt either.

A friend of mine pulled a 13.99 in his '65 GTO 'vert 4 speed- 389, 77 heads, Trips, Summit 2801 cam, RA manifolds, 3.55 rear .... and badly slipping clutch. Your '66 should be a bit lighter if it's a hardtop, the '66 Tripower flows better than the '65 and hopefully your clutch is holding.

[Tpower66]

goatless don't care about stock look. I opened up logs. Which cam?

[Tpower66]

can't keep up with 2010/11 camaros/challengers much less the new ones.

[goatless]

Well, Hell, if you don't care about the stock look then throw on some E-heads, RPM intake with a Holley, big roller cam and some headers. Good to go!

[Tpower66]

Originally Posted by mchell

did what you are trying to do long ago....

just heads???......be a stretch, unless you're willing to up the compression(waaaaaaaay up).......realistically, you're gonna need heads, cam, exhaust and some gear to achieve your goal with moderate compression.....as well as some good tune....or get some cubes

Which heads, cam and gears do you suggest.

[Jerry H.]

I'll throw this in: My 65 has the original 389, with 3.55 posi. It was original a 2 speed auto, I swapped in a TCI 'streetfighter' turbo 350 with a 2300 stall. This is just one step up from a stock turbo 350 tranny. The engine was supposedly rebuilt when I bought it; with 9.0 hyper pistons, 068 cam and hardened valve seats. Everything else was stock. Now I'm running an Offy dual quad intake with AFB's with Jon Hargrove kits. Although it runs smooth, I don't know if this setup runs any better than a good tuned set of trips.

Shifting at 4800, our best time so far has been a 14.2. I don't want to take a chance of hurting the original engine, but I believe if we ran it up and shifted at 5200 we might be in the 13's.

[goatless]

Originally Posted by Tpower66

goatless don't care about stock look. I opened up logs. Which cam?

I don't know what would be good for a 389, but I'd probably go with moderate sized hydraulic roller. I'd think with some careful choices you could get low 13s maybe high 12s and still look totally stock. If it were mine though, I'd through more cubes at it!

[mchell]

Originally Posted by Tpower66

Which heads, cam and gears do you suggest.

.. any iron dport head ported to flow at least 230(240 would be better) at .500 lift, fill the exhaust crossover in the head with aluminum.....compression at 10 to 1(real 10 to one, no guessing)....you will need a healthy cam, in your case I might stick with a 041 clone(crower), 3.90 gear, headers and an x system no smaller than 2.5" .....

don't know squat about those tri-power setups...its gonna need some tune

depending on where your piston is in the hole you may have a ping monster.....devils in the details

beware putting fresh heads on a suspect bottom end as it will likely become a smoker...

[steve25]

If its stock and has more than 40k miles on the motor the very first thing to do is change the valve springs, as they are done for rev`s over 5000 due to normal pressure loss, and the motor needs to go to 5600 cleanly.
A big mistake that folks make when they take these street cars to the track is that they hurt the motor little by little, run by run at the end of the pass when the combination of hitting the brakes hard and the non baffled oil pan let the oil pump pick up become uncovered.
When making runs at the track these motors should be over filled by one qt which was a factory fix for the early 60s race motors that where failing after 3 to 4 passes down the track!
You may drop off some HP due to windage loss, but the motor will live to make another pass.
After this its time for steeper gears, or shorter tires.
The fastest way to pick up ET with these cars is by means of 60 ft times. this calls for more torque and faster revs.
Basically every gain of 1/10 in 60 ft times will be X 2 at the end of the run, your MPH may drop, but the overall ET will pick up!

[Ron H]

No concern for the stock engine?

Myself I would build another engine.

Why stay with the 389 when you can work a 400 or 455 into the 12's pretty easily?

[Tpower66]

Originally Posted by Ron H

No concern for the stock engine?

Myself I would build another engine.

Why stay with the 389 when you can work a 400 or 455 into the 12's pretty easily?

Yes I care about the stock engine. Just asking if reworking my 093s or other heads would help. I agree a 400/455 would be a better build.

[Ron H]

Yes porting your heads or another set will help. But with the stock bottom end you could be looking for trouble.

If it is numbered, etc you may want to do another build so that one stays alive.

The more you make and beat on it the higher the chance of damage occuring.

My first thought was a set of KRE D Ports. Lighten the front end and make more power. Then if you decide to go to a bigger short block you can work the heads for bigger gains later.

[steve25]

Those heads in stock form flow 190 cfm@28" on the Intake side.
I have out fitted them with a 1.94" Chevy valve, ported them and opened up the Inatke valve side of the chamber like the latter 1967 #067 heads.
This work resulted in a flow gain up to 250 cfm@28" while still having a amount of port will thinkness to hold up in every day street use.
When ported to hit thses Intake flow numbers the Exhaust side needs a large amount of work also.
This amount of flow gain should make for at least a 15 to 20 HP gain per cylinder with a change to a cam of .500 to .550" lift and a Intake duration jump to around 225@.050".

[goatless]

I've got to say that I'm a little confused by the OP's intentions? Wants to go faster and is not concerned with stock appearance but wants to keep the stock bottom end?

I think he can reach his goals of mid 13s and still look totally stock.

Once you go and throw aftermarket heads into the mix, I'd pull the original 389 out and set it in the corner and go big.

[Tpower66]

Originally Posted by goatless

I've got to say that I'm a little confused by the OP's intentions? Wants to go faster and is not concerned with stock appearance but wants to keep the stock bottom end?

I think he can reach his goals of mid 13s and still look totally stock.

Once you go and throw aftermarket heads into the mix, I'd pull the original 389 out and set it in the corner and go big.

I mis-spoke when I said I didn't care about the stock look. What did you have in mind when you said "I think he can reach his goals of mid 13s and still look totally stock".

[carcrazy]

I feel like something is amiss. Seems to me that with proper tuning, the existing combo (assuming everything is in good condition) should run low 14's or so. Have you worked with the ignition curve? My 67 with more gear, 744 cam, headers and holley carb could run low 13's all day long. After doing some port work and blueprinting the motor it would run in the upper 12's.

[se428bandit]

http://youtu.be/YuwCb140w0M
A 389 can run mid 13's,you just need the right camshaft and a tune. Personally, i would pull the 389 (if it's original) and use a '66 421 block and the 093 heads mildly ported with a decent hyd camshaft and might have yourself a 12 sec car. You have a few engine builders here on PY,give them a call.
The one thing you might want to invest in is 1/2 fuel line from the tank to the fuel pump and a Robb Mc fuel pump. Inline tube made me a 1/2 fuel line with the factory bends and it fit perfect.
http://www.inlinetube.com/Preformed%...s/ocatalog.htm