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Dec 13, 2004 | 12:50 AM

trkdrvr

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rearend

ok another silly question. what does the 3.73 rearend mean? what is that made for towing or hotroding? the truck had a camper on it before i bought it. thanks alot anyone.

Dec 13, 2004 | 12:59 AM

mulletbob69390

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not the best for highway, had a 70 f250 2x4 worked good for me

Dec 13, 2004 | 01:02 AM

trkdrvr

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so does that mean it needs to be changed ? i have a new 352 in it.

Dec 13, 2004 | 05:54 AM

jowilker

Fleet Owner

Joined: Jun 1999

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From: Creedmoor, North Carolina

Gil, It is the engine/rear axle turning ratio.

Your engine is turning 3.73 times to your tires one.

Someone else can splain the finer points.

John

Dec 13, 2004 | 12:29 PM

Freightrain

Lead Driver

Joined: Jan 2003

Posts: 9,893

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From: Ohio

The "higher" the number, the more revolutions the engine turns to make the vehicle go forward at the same speed(mph).

Your 3.73 is a good gear for mild pulling, a bit steep for highway cruising/good gas mileage. The lowest ratio is 3.25, the highest was 4.11 from factory(some even had 4.56).

Depending on how tall your tires out back are will also affect that ratio. IE: your 3.73's with 30" tire will turn "X" number of revolutions. IF you put a 25" tire on it, it will turn 17% FASTER than "X" since the tire is shorter. In reverse of that if you put a 35" tire it will turn 17% SLOWER than "X" because the tire is taller.

Hope this helps.

Dec 14, 2004 | 12:19 AM

trkdrvr

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ok i get it now im a newbe to this just wanting to know about my truck. i have 16 inch tires on the rear. dont do much freeway driving. the truck had a camper on it thet is maby why it has a gear like that. thanks for the help you people give me. it will help me alot. if you dont mind what kind of gears should i buy to make the 352 do good burouts if needed. i know i might buy a holley carb soon. that will do some of the trick.

Dec 14, 2004 | 01:01 AM

"Beemer Nut"

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From: "Islander"

rear gears and trans

It's 37 years old, don't go and tear it up. Your a little short on torque with a 352, 4.10 gears will get you 10% more torque to the tires. Theres a "but", you will loose 10% in highway speed for the same rpm's and gas mileage will suffer. 3.73 looks perfect with just a camper, if you tow also then 4.10 would work better for a 352. A torque designed 390 or 410 would pull harder (alot more torque). What do you have, stick or auto? If it's a Cruise-O-Matic trans you will destroy it burning rubber, a C-6 is stronger, cheaper to rebuild and more common. A friend of mine just got his 67 back that had a wasted Cruise-O-Matic with alot of hard parts damage, total repair with labor, $1,750. Makes you want to "burn rubber". Done preaching. Carl.......o&o>.......