OK, Where can I get a 3:73 ring and pinion for my Ford 9 inch rear. I can find 3:70 but who sells 3:73? Thanx.
Um... the difference between a 373 and a 370 are so slight that you wouldn't be able to tell them apart. Ever. I mean, without sophisticated computers obviously.
They are the same basic gear......... 3.70 is a 37 ring and a 10 pinion 3.73 is a 41 ring and a 11 pinion You could NOT see the difference on a Tach at 70 MPH or feel the difference. I know of no 3.73 for a Ford 9 inch
[ QUOTE ] I think he's right- 373 not available in a 9" [/ QUOTE ] So did I... until I ran across Randy's Ring and Pinion. Never dealt with them, but their catalog shows a 3.70 and a 3.73 ratio for the 9" Go here: Randysringandpinion
Even in a 4x4 3.70 is close enough to 3.73 to work fine.Ford used 4.10 rear, 4.11 front, 3.70 rear, 3.73 front, 3.50 rear, 3.55 front, 3.25 rear, 3.23 front. There will not be a noticeable difference. Randy's does have the 3.73 gears, along with many other ratios no one else lists, they are for fine tuning the gear in circle track racing.
know why they did that? to take up driveline slack between the frt and rear diffs when in 4X4. at least thats what they tell me...
My 77 Ford 3/4 ton 4x4 had 4.10 front and 4.11 rear. The higher gears in front were due to the front wheels traveling at a faster speed on moderately sharp corners and they pulled better on loose surfaces. Same ratio both ends has the front end plowing on some corners.
You might try richmond gear. Don't have a number on 'em but if you call Summit Racing they can hook you up. One of the reasons for slightly higher gear in the front of a 4 wheeler is to keep it going in a straight line in the sloppy stuff. The fronts pull the rears.
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