Differential Gear Changes

[decooney]

Hey Art,
totally cool, no problem. Its all on the upside. My interest comes from many comparisons with friends who went too low on 1st gear with Tremecs and others that had lower rear gears like 3.54s and went back to 3.31s or 3.08s - at an extra expense. Jag rears in most of them. If this can help you to save some time, money, and frustration, the discussion is worth having and reviewing. I'm going through this with a friend that has 3.54s right now. Last weekend we had 4 Cobras on some back roads, and reconfirmed again the pros/cons from starts, twisties, and minimal hwy/interstate driving. Also... lots of debates about the ultimate rear gear and 5speed combination, with the right overdrive gear for those who want 5speeds. We all seem to be looking for the extra nice sweet spot and feel its worth more fine tuning - if there is anything left to confirm or change. I failed to mention that for me cam selection and carb tuning was just as important as it relates so closely to gear ratios and how it all works together for the final recipe. I'd be interested to hear about the number of teeth on your ring and pinion if you ever get a chance to pop the cover... to know for sure.

As for fuel, you have it made my friend. We get to use 91 unleaded and/or mix race fuel 100/110 or Octane booster. We have great roads here to drive on, but the fuel situation is a challenge on the street pumps.

[fordracer]

Kinda off the subject but Duane your car is danged nice looking. I also agree that a lighter car needs a higher gear. I personally would go with the 3.31 . I've had drag race cars and have also played with gear ratios. A 3.73 with that ultra low Tremec first makes for some nice smokey burnouts but the car just doesn't go anywhere.

[foothills gary]

It seems in good old Cali,Union 76 premium is about the best we can get at the pump.HotRod maggazine does most of their testing of street motor buildups using this.I remember the good days of the 60's,working with my Dad at Sunoco,pumping high octane Ethyl(or was it Ethel,I can never remember).Every streetbeast one could imagine would prowl in,starting at about 7p.m.,until closing.They all wanted to run light,so a couple of bucks worth(at 29.9c per gal ) would get them throgh a few stoplight wars.You are one lucky dude,Art!

[decooney]

Originally posted by fordracer

A 3.73 with that ultra low Tremec first makes for some nice smokey burnouts but the car just doesn't go anywhere.

fordracer said it best in one sentence. "just doesn't go anywhere" is what I was trying to say about gearing too low in a light car with a big block. Thanks fordracer.