2.88 jag rear

[427 S/O]

Anybody run a close ratio top loader
with a 2.88 jag rear, gimme the ups and downs.

[Bob Putnam]

You better have an engine that is totally docile. First gear will be good for 70+ mph at 6000 rpm.

Which means that at a 1000 rpm creep, you'll be going 12 mph. Lots of clutch slipping at takeoff, and likely a few embarrassing bucks and stalls.

[mr0077]

Pat, Bob is right...I have a close ratio with a 3.31 rear and love it, but my big block has mucho torque and I still need to pay attention when taking off. I don't recommend anything lower than 3.31 w/a close ratio...

[427 S/O]

Thanks Bob, what about a wide ratio top loader.

[Tom Wells]

Hello pathenry,

Here's a good use for a 2.88: a 521/C6/low stall (2000-2200rpm) converter.

Plenty of torque and a good idle. It'll light'em now from a 5mph roll all the way up if you want to.

With a manual trans you'd need a pretty big, tame engine to have an easy time on the street. Bonneville would be pretty good though

Tom

[aumoore]

I have a Hunter Cobra with a 85 vette rear end that came out of a automatic car. It came with 2.73 rear gears and it was a bear to launch with my 5.0 motor. With my SD T-5 trans(2.95 first gear ratio) it was good to about 55 in first. I rarely used 4th and the overdrive 5th was useless at anything under 80. I changed to 3.73 gears and what a differance. The car launched so hard with the new gears I found out I needed jet extenders in my carb. This never happened with the 2.73 gears.

I agree that with a manual trans you need gears over 3.00 and a 3.31 or 3.55 would be perfect with a big block.

To figure out the final gear ratio multiply your first gear ratio by the rear gear ratio. Here is an example:

my old setup 2.95(first gear) X 2.73(rear gear)=8.054 motor rpm to one wheel revolution

my new setup 2.95(first gear) X 3.73(rear gear)=11.004 motor rpm to one wheel revolution

[Bob Putnam]

Pat,

Our preference is to use a 3.31 dif with the wide-ratio Toploader. A 3.07 dif is about as low as I would combine with a 427SO and wide ratio trans.

[Geary L. Sarno]

With respect to your question of using a wide ratio toploader and a 2.88 Jag rear, if you do the math this combination would give a 1st gear ratio of 8.01 to 1. In comparison a typical 3.31 rear with a close ratio toploader would yield a 7.68 to 1 ratio. The 2.88 rear would have numerically more "grunt" in 1st with an engine loafing direct drive in 4th. The only major drawback I can see would be losing the "kick in the ass" accelleration in your top gear. Personally I like the 3.31 with close ratio combination. Good streetability and performance - Aggressor

[427 S/O]

You know......It's really not bad, I built a torker motor that plays out at about 6000. No bucks or stalls and when it hits
about 1800 rpm, it's a rocket.