4.10 gear question...

lang williams said:

this has me thinkin of getting 390's instead of 410's.....the car currently has 456's in it an 28" 275/60/15 dr's

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That's a really minute difference....i wouldn't even bother personally. I'd go all the way down to 3.73. I'm actually thinking about it myself (4.10s and a 5 speed here) simply because i want a more even powerband...not just all take-off and no top end.

I'm trying to figure out what gears are in my rear! I did an aod-t5 conversion and holy ***** am i geared low. I was thinking that i was in the 4.11 range and now after reading Talladams post, Im almost sure of it as i turn similar r.p.m's at 65 (maybe a couple less like 2250...but im running on 215/40/17's) It's tough though since i commute on the highway with it everyday! But it is alot of fun. Is there a way to tell what gears they are, without disassembly (besides the pumpkin cover im expecting to remove that)....thanx guys im new to the forums and am gathering tons and tons of invaluable info.

Find out exactly what RPM you run at 60 mph and your tire size and it can be figured out with a little math.

Jack up the rear end, put it in neutral, disengage the parking/e-brake, mark the driveshaft, and rotate it. Count how many times the driveshaft turns per one revolution of the tires. Three and three-quarters of a turn is going to be 3.73's; just a tad over four turns will be 4.10's; three and a half turns will be 3.55's; etc.