I have a 68 Pro Street with a big block. I run consistent mid to high 12's. I would like to possibly run super street next year. My decision will be based on whether I can get enough power out of this motor to do it. The present set up is an LS6 configured as follows
4.280 bore, 4.00 stroke, GM square port heads with 119 cc chamber volume, 2.19 intake valves, 1.88 exhaust, GM forged 7416 crank, Clay Smith 280 hydraulic cam,duration @ .050 is 230 both intake and exhaust, runs stock LS6 intake manifold with holly 830 carb. Jetted with 70's for both primary and mechanical secondaries. It runs a TCI TH400 with 2500 Hughes converter through 4.88 rear end gears.
The car is consistent, but in order to run a 10.90 index for super street I need more. With out going into the bottom half and changing pistons, what can I do to achieve this goal or would I be better off with a new motor.

At the minimum you will need to do these things.

1. Bigger cam, what you have is a street cam, you will need something like a roller or solid cam and compatible valve train equipment.

2. Converter and trans brake, maybe even a swich to a Powerglide.

3. Put the car on a diet, take out whatever weight is unnecessary, ie. heater, PS, window regulators etc.

I assume you have a roll cage and other safety equipment necessary that is capable of passing NHRA tech. Contact your local division headquarters to get a copy of the current rulebook and find out where you can have your chassis certified.

Steve R.

Thank you for your reply. I have already done the diet trick except for window regulators. I forgot to mention that it currently is juiced by a MSD 6. Could you be a little more specific with your suggestions for components. Should I go to a single plane manifold? What size carb? What stall converter and cam?

I would also like to know about your suggestion to switch from the TH400 to the powerglide.

I have already done all the safety stuff, like cage, belts, helmet, etc. Just need to get the power

Thanks for your help

<BLOCKQUOTE>quote:</font><HR>Originally posted by Steve R:
At the minimum you will need to do these things.

1. Bigger cam, what you have is a street cam, you will need something like a roller or solid cam and compatible valve train equipment.

2. Converter and trans brake, maybe even a swich to a Powerglide.

3. Put the car on a diet, take out whatever weight is unnecessary, ie. heater, PS, window regulators etc.

I assume you have a roll cage and other safety equipment necessary that is capable of passing NHRA tech. Contact your local division headquarters to get a copy of the current rulebook and find out where you can have your chassis certified.

Steve R.<HR></BLOCKQUOTE>

What size tire do you run? The 88's seem a bit much for a big block car. Depending on your budget, I would use the Comp. 11-605-5 Solid flatt tappet cam. It is conservitive at 270/276@ .050 w/.637/.631 lift on a 108. Then use a 4500 stall/Super Victor manifold and get the CFM about 950 w/ a modified 850dp or an HP series Holley. Then lose some of the gear and let the motor pull the car. A roller would make more power, but at about 600 bucks more and having to change springs on your heads. If you and your car are at about 3200 lbs, you should go upper 10's. Super Street cars are a whole new ball game. They are back halved w/ throttle stop, slowed down Comp. cars with the power to go well into the 9's. Even dialing in a 10:90 as they do, you would need to run the number dead on within .001 to be competitive. Just my opinion, but your car would run good. Galen

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S/B Chevy Lover
67 Camaro street car
10:50's @ 128 on motor w/383 cid
79 Z28 Restored stock apearance
13:40's @ 101 stock exh.& intake
smog legal
Camaro Lover

Thanks for your reply. Currently it has Mickey Thomson Sportsman tires that are 31 x 18.50 x 15. I have run Goodyear racing slicks that are 33 x 18.50 x 15. If I change, I will be going with a Hoosier tire in the same size as the Goodyears. Do you still think I need lower gears? What is your recommendation