Thread: head advise

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Hey everyone,

My name is DJ, I have a 383lt1 and was ondering if someone could help me out with a cam and headwork selection.

For some basic info on the motor; its a 383 ni crank, forged 6" i-beam rods and forged flattop 11:1 comp. pistons.

Right now the heads are stock with a stock cam, but I want to run nitrous on a weekly basis. So here are the ideas Ive been toying with:

1) 1.6 rockers on the exhaust (to scavenge all exhast) with extreme port and polish, and aggressive cam with identical intake and exh. lifts.

2) stock 1.5 rockers with larger valves on the exhast with extreme port and polish and similar cam.

3) extreme port and polish with aggressive cam with higher exhaust lift than intake.

I would like to go with the full setup, 1.6 rockers, springs, valves, and porting, but my wife is limmiting my budget. I should also mention that I have 4.10 gears and a turbo 350 fully built with a 2500 stal. Also its carbbed

Any advice would be truly appreciated. Oh and I dont care about emmissions as this is a track toy.

Thanks everyone.

Are you running 1 3/4 primary full length uncapped headers?

Hi cdjspeed;
Sounds to me like you have a pretty good handle already on what needs to be done. First money I would spend would be on professionally porting and polishing the heads to flow 300 cfm intake @.600 and up-size the valves to 2.08 and the exhaust to within 80 % of that with 1.60 valves.

The cam can be on the aggressive side because of the large displacement size of your motor. The larger the pump, the less radical the effect of the cam. Therefore I would opt for a cam in the area of the following specs. Intake- 260 degrees @.050 and .600 lift rated with 1.5 rockers and exhaust- 266 degrees @ ‘050 and .620 lift rated with 1.5 rockers. Then I would install 1.6 rockers. Lobe separation @ 113 degrees. Installed with 4 degrees advance.

Your gear selection and torque converter look good. What kind of car and how heavy is it? What is the size of the combustion chambers?

As for the wife data, this hinders most racers. You need to either eliminate this input, or find a way to cheat on her. DO NOT get a divorce, for then all money will be gone.