79 Thunderbird 5.0 3spd gear questions

[Lost216]

just got a 1979 ford thunderbird with a bad rear axle. Since the gears have to be replaced, I want to put some lower ones in. What i'm after is hard, fast accelleration. I don't need high top speed, 90 is plenty, and I'm fine with turning up to 2K at 60 MPH, as I don't really see this being a daily driver. It may be, and if the X breaks down it will be, so I can't afford to go all-out. It only has a 3 spd tranny, so again, I can't go all out on it. 3.73 seems really popular, but that sounds too tall to me. I'm used to thinking in 4X4 terms, so if anyone can give me some advice I'd really appreciate it.

 

[MountaineerGreen]

I can only assume the final gear in the trans is 1:1, so depending on tire size, you can figure out what gears you want. I would say 4.10 would be way too deep without doing calculations, 3.73 or 3.55 may be a good choice.

I had a 95 T bird with 3.08 gears and it would have screamed with 3.73's.

 

[Lost216]

thats what I was afraid of. Keep in mind, though, this is a heavy car with a small motor (when you look at the car). I'm sure the new ones are lighter

 

[james t]

Assuming a 26" tire (that should be really close to whats on there)-

With 3:50 gears-
You will be turning 4000rpms at 88mph
.........................3000rpms at 65mph
........................ 2000rpms at 45mph

With 3:08 gears-
You will be turning 4000rpms at 100mph
..........................3000rpms at 75mph
..........................2000rpms at 50mph

 

[rookieshooter]

What i'm after is hard, fast accelleration.

+ heavy car = 4:10 anything less is for grocery getting.

 

[BrooklynBay]

You will need to replace the speedometer gear to match the new axle ratio, or you might not have an accurate speedometer.