Eric Anderson

iTrader: (2)

I'm running a LS1 /4L60E in my 68 cutlass. I've got a 3.08 posi out back, that was a nice combination with my former TH350 trans. The rear is now dripping and now needs a rebuild. Time to consider another ratio since I've now got overdirve.

I'm running 17" wheels with 245/45 tires if I remember right.

Does anyone have a feeling as to if deeper gears might gain me some low end fun and possible fuel economy? If seen the term "lugging" thrown around. I'm guessing some will say that I need more highway RPM. This thing turns awful slow on the highway, I guess its probabaly similar to my Tahoe though..


What are you other A4 guys running for gears?

Tuffguy610

iTrader: (2)

I don't have a conversion car, but I do know that my 2.73s are probably the best highway gear you'll get with an automatic. For your car, which is probably alot heavier than mine, I'd go with something like a 3.42, 3.55, or 3.73 with the 4L60E. To help you out, I'd look into one of those gear ratio RPM calculators that they have on here (somebody might be able to point you in the right direction of those or you could search for it). If I remember correctly, 3.73 gears in overdrive will put you somewhere around 3,000 RPMs at 80 mph on the highway. Hope that helped you, but check that gear RPM calculator.

zman1969

iTrader: (91)

rebuild or maybe just resealed? is there anything wrong- noises or posi is inop? If all working corectly I'd reseal it. If its posi is weak id buy a 71-72 cutlass/skylark rear and build that its a 8.5 and parts are lot easier to come by for them and they are alot cheaper as a result. I have 2 of those rears on hand if you want one built PM me - hope this helps you out
Oh btw I wouldnt go any lower than 3.42 that tranny has a very low first gear!