The car is a 66 coupe, it has a mild 351w, c4 with a shift kit, 8" open differential with 3.00 gears. Right now it has 245/60/15 radial t/a's. I like the cruising rpm of the 3.00 but i dont like how slow the car is off the line, im going to put a track-lok in it and figured why not change the gears at the same time.

My question is what gear ratio would be good for my car? Id like it to take off faster, but not kill my highway rpms.

 

I'd like to eat more and exercise less; but I don't want to gain any weight. ;-)

Maybe I'm missing something but I don't understand your question. Deeper gears will drive your RPM up on the highway.

Unless:

You go to a T5 or some other type of overdrive transmission, a Gear Vendors O/D unit, or something along that line. Then you can put steeper gears in the back end and still slow the motor down on th highway.

A different driveline is the only way you're going to get more torque to the wheels without running at 3000 RPM at 55 MPH.

 

Put an AOD or 4R70W and you'll get the best of both worlds.

 

Your making me think cuz it's been so long since I've had the car out. I've got a 3:25 tracloc, C4, and sit at 3200 RPM @ 65 MPH. If my memory is right. Your easily going to hit 4K RPM the second you put your foot in it. Forget anything above 3:25 if your driving highway much. Of course, it's only $3K for a complete tremec swap out, or $2.5k for a gearvendors OD. Go for it. The gear change is cheap compared to everything else, I think I paid $700 for my complete 3rd member.

 

Hi,
Your wheel dia is 26.5". Running a C4 with a 3.25 gear will put you at about 2671 RPMs at 65 mph. Unless you make a tranny change the 3.25 is about where you want to be.
Just so you know, running a T5 with .63 5th will net you 1590 Rs.