1971 Camaro Diff Ratio

Predator4 · Apr 26, 2013

Hi all... we have a few things together for our Camaro build but are not sure about the best gear ratio for the rear end. At the moment we have 2.73 gears. We think that these may be to tall for best performance with the cam. Would be happy to stick with these if they will work OK. We will use the car for cruising and take it to the strip a few times.
71 Camaro 350 SBC 350TH Trans. 3000 Stall
Comp Cams Magnum 280H Hydraulic Flat Tappet Camshaft
Lift: .490''
Duration: 280°
RPM Range: 2000-6000
JEGS aluminium heads 64cc 170 intake runner 2.02 intake valves.
1.6:1 Roller rockers
Compression Approx 9.4:1
Performer RPM intake
750CFM Quick Fuel Slayer Carb
1-5/8 Headers
You recommendation would be greatly appreciated.
Cheers Wayne

big gear head · Apr 26, 2013

3.42 is a very popular ratio for most street cars that will be raced a few times. I wouldn't go any farther than that without an overdrive transmission. You will also want to get an Eaton Posi if you have a standard differential right now, and a good installation kit. I'm guessing that you probably do a lot of shoping at Jeg's, but I do not recommend getting rear end parts from them or Summit. Go to Tom's Differentials or Randy's Ring & Pinion for rear end parts.

dogwater · Apr 26, 2013

With 3.42's an a TH 350 your rpms at 70 MPH will be 2900. I got tired of listening to my engine spining that fast. I changed to a 700r4 an kept the 3.42's now at 70 my rpm's are at 2100. Nice rpm drop.

Predator4 · Apr 27, 2013

Thanks for your help with this. We have the 2.73 gears at the moment will they work with the engine buid as described? We are on a very tight budget.

vinniekq2 · Apr 28, 2013

14 second bracket car

You can race the car as it is and just enjoy the drive. You will have a tonne of fun and after a season ,then decide if quicker is more fun.I can understand wanting to move to the 13.99 bracket and making everyone catch up.

big gear head · Apr 27, 2013

It will work, but performance will suck. Your cam won't like that gear much, and the converter is going to slip all the time.

Predator4 · Apr 28, 2013

Looks like I will need to spend a bit more on new gears to get everything to work well together.
Thanks again for the help.

Cheers Wayne

1971 Camaro Diff Ratio

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