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73-87 Chevy _ GMC Trucks => Performance => Topic started by: 85ChevySleeper on June 19, 2004, 12:30:00 am

Title: Rear end gears
Post by: 85ChevySleeper on June 19, 2004, 12:30:00 am

What would be a good rear end gear ratio if a guy wanted a good take off off the line and wanted good gas mileage?

Title: Gears
Post by: 77 K30 Crew Cab Dually on June 24, 2004, 06:18:00 pm

It depends on what engine and powerband that engine has that your using. What engine do you plan on using?


Dave

Title: Re: Gears
Post by: dopey454 on July 08, 2004, 09:51:00 pm

check this out www.auctionworks.com/stor...id=6491258

Title: Re: Gears
Post by: roundedline on July 09, 2004, 10:57:00 am

I have found (without overdrive) 3.42 gears are a pretty good ratio.

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

Title: Re: Gears
Post by: TORQUERULES on August 25, 2004, 07:47:00 am

I had 3.73:1 and 28" tire. got 12.14mpg
Went to 3.73:1 and 26" tire. got 13.4mpg
(makes it like 4:02:1)

I ran my truck harder with the shorter tires.
Plus was turning near 3000rpm going to different towns.
For some reason I got better mileage.

this is with a 3 speed and a mildly modded 357SB.

I'm even pretty sure I got worse mileage with my stock 305 and 3.08:1 rear gears.

my motor doesn't mind spinning higher revs. The low gearing makes my engine think my truck is lighter.

No acceleration difference 3.73:1 vs 4.02:1

3.73:1 lays 5 foot black marks off the line.
4.02:1 lays 50 foot black marks off the line.

had a 305
have a 357
want a Big Block

Title: .
Post by: bored and stroked on August 31, 2004, 02:02:00 pm

No overdrive = 3.07's. Overdrive = 3.42's/3.55's.

Title: Re: Rear end gears
Post by: shortchevy84 on September 27, 2004, 10:39:00 pm

hey, i was wondering if anyone could help me. i got a 350, with flat tops, mild cam, and performer air gap manifold. i've got lots of power it seems, but i can't spin my tires off the line. going around corners sure, for a good 5 seconds, but off the line, nothing. possibly new rear end in the works??i have what i believe to be a stock 84 short box rear end. no idea what the gearing ratio is. i tried the self test, by counting the rotations of the drive shaft to one turn of the tire, but i didn't get a number close to any of the rear ends i have seen. if i remember right, it turned 1.5 times for one turn of the tire..? can't remember it was a long time ago. anyway, i was wondering if anyone could recommend a good diff gear ratio for plenty of tire spinning but still with good mileage. and a good place to start looking.(year make and model of vehicle to be found on)..picky picky eh!! anywho, any help is much appreciated

Title: Re: Rear end gears
Post by: 1976Scottsdale on October 17, 2004, 08:59:00 pm

I like my three rearends- 3.40 posi, 3.73 posi, and my personal favorite the almighty 4.11 posi.