whats up guys i have a 76 camaro with a 327 bored out, big cam, heads, rolller rockers and all that other good stuff haha. i have a muncie 4 speed on it right now and its great. my question is what would you all think about putting a posi 3.73 rearend instead of the stock 2.73 rearend? would it be worth $200? im not gonna be screaming at 4500 rpms going only 40mph am i? has anyone tried this setup? how big of a difference is this gonna be?

thanks alot guys
kinder

 

Well, according to this calculator site that I used, with a 3.73 rearend, and 4th gear in a muncie 4 speed, at 3500 RPM you would be around 70 mph. and about 2000 rpm at 40 mph.

I too was looking at options for a rearend. i now have a 2.41 rear with a turbo 400. and I do about 35 mph at 1500 RPM. haha. If only it wasnt dead off the line.

I found that a 3.42 rear with a 700r4 would be better off the line than a 4.10 on a turbo 400 and have better mileage (overdrive gear) than my current setup.

 

I would think the 3.73 is just right. That 327 probably won't have a lot of low end torque. The gears will help with that. Not that it really matters what tranny you have there all 1 to 1 in high gear. Unless we're talkin something with od. I like my BW T10 and will also be running a 3.73, although it is what came with the car and I don't plan on changing it until I put some miles on it. That way I will have a feel for the way the motor pulls and what kind of r's its spinning when I cruise. I do think 3.73 is right for that motor though.

 

What size tires are you running? The tire diameter has a bearing on your final rpm to speed ratio, so any answers given are just guesstimates.

 

hey just wanted to know what site you use for calculation. thx

 

here's a popular site people use:
http://www.thirdgen.org/calculations

 

http://www.angelfire.com/fl/procrastination/rear.html
http://www.car-videos.net/tools/speedrpm.asp
http://www.thirdgen.org/calculations

and then...http://www.bgsoflex.com/speedo1.html

 

The 3:73's will be a good around town gear ratio, and if you're not doing tons of highway cruising they'll be fine occasionally on the open freeways. I wouldn't want them if even half my driving was freeways, as the engine will be working at those higher RPM's too much for my liking.
The price is great at $200. A real bargain for a 3:73 posi.

 

when you upgrade your engine and you have to change the differential, do you also have to upgrade the gears? because when you upgrade the gears doesnt it reduce your speed?

 

i meant ring and pinion. and where do those even go?