Our Electra has 3.23 gears and we would like to get more economy out of it on the highway as well as drop the revs. I don't want to reinstall the 200R-4 as it has a couple of issues and finding a good used one around here is almost impossible. The TH350 in the car now has less than 20K easy miles on it so I want to stick with that. I was thinking on installing 2.73s but am wondering if this may be too high. I know that sedans used to often use 2.56's but I don't want to go that high. My car has P225/75R-15s which are 28.28" high. If I go to this site: http://www.westerndiff.com/rpm.html and use the rpm calculator @ 60mph 3.23s 2364, 2.93s 2145 and 2.73s 1998. When diving the divided highways up here you can easily drive at 70mph which tachs the engne at 2758! The engine is stock and I am considering putting duals on it and I may do a little towing but nothing over 2,500lbs. Any opinions on this. Thanks, Greg
I think you might have a hard time finding the gears for anything taller than 3.08. I'm a fan of tall gears (I think my 2.56's could be even taller) but you might have a hard time finding the ring/pinion setup.
I think 2.73 will be a noticeable change for you. 3.08 is pretty close to 3.23. what axle is in the car?
No problem, you can get whatever gear you want for that rear. Here's a used set of 2.73's on E-bay http://cgi.ebay.com/ebaymotors/RING...LT-8-5-GM_W0QQitemZ150253530346QQcmdZViewItem
I've got 3.08's in my LeSabre with similar size tires. Hard to beat for an all-around gear ratio, cruising or towing. 3000rpm gives me right at 80mph.
