Need a little help here deciding what overdrive gear would be better suited to the LT1,I have a completely stock 93 Vette motor w/39,000 miles it will have a cold air intake and long tube headers. This is going in an 68 Firebird with Tremec 5-speed and 3.42 gears with 26 in tall tires. I am trying to decide between the TKO 600 rr with an .82 OD that will give me a 2500rpm cruise speed at 70mph. or the TKO 600 with an .64 OD that will give me a 2000rpm cruise speed at 70mph. I guess the best way to describe what I want is to say that I don't want to have to downshift to make a pass at highway speeds and I plan to drive the car 2-3 days a week to work which is a 70 mile round trip. Any opinions would be appreciated. Thank you.
Mike

 

Motor staying stock? If so I would take a cruise speed below 2k if I could. That being said all of my setups have cruised the smoothest around 2000.

Even now with my big cam the sweetspot is always right @ 2k no matter what gear it is in.

Since you are stuck with the 5 speed I guess that adds to the issue. With a t56 like all the 4th gens have you get 2 overdrives. Going from 1.0 to .64 is a pretty big jump for 1 shift.

I dont think you will have a problem "passing" with either gear, but .6 is pretty puny and it wont be a racecar in OD. Its been so long since I have had a stockish motor, but now I wouldn't think of passing without dropping at least 2 gears.

Sounds like fun, keep us updated.

 

Sounds like you will probably not be running a catalytic converter. In that case, that motor will be LOUD, at least with the regular series Flowmaster or equivalent. Depending on how much you like noise, I would vote for a cruise RPM of 2000 rather than 2500. You should still have plenty of torque for passing at 2000 and probably get better gas mileage as well.

 

Thanks for the opinions. I also called a few guys that are driving LT1 powered cars and they were in agreement with what the two of you had said so I ordered the TKO 600 street version with the .64 OD and the 2.87 first gear. I will probably be back asking questions as I move forward with getting the motor wired and ready to run. Thanks again for the help.
Mike