rear end gearing

[351windsorbronco]

ok, i have a 1983 Ford Bronco Full size with a 5.8 windsor in decent condition that i am truly attached to. right now i am probably puting out 320+ hp and 390ish torque. I have 31 inch tires on a 15x8. I want to increase my rear end gears but not sure how big i should go. any suggestions. I have found 3.73, 4.56, 4.11 and others

what should i run i want low end torque and power for pulling my 30 ft trailer with a 26 ft . boat on it.

i want to know what to run and also a good place to get this stuff with afordable prices, prefer to be new. I think its got the 8.8" am i correct?

please help me and you will be greatly appreciated

thanks guys (and girls)

 

[Justshootme84]

Welcome to Bronco Zone!!! As a general rule, you're looking at 4.10:1 gears for 31-33" tall tires and towing. That's assuming stock horsepower of 145 on the 83 351W to stay within the powerband. My feeling is that you can make up for the gear reduction with a large HP increase. I was pulling 35's with a 250HP 351W H.O. and stock 3.50 gears in the Ford 9" rear axle.

If you have 3.50 or 3.55 gears already, you may be fine with those or only the 3.73's. I'd be interested to know what mods you have to get that extra power (as would other folks I'm sure), and whether you have the Ford 8.8" rear axle or the Ford 9". Both were offered in 1983, with the 9" being stronger, IMO. The 8.8" has a bolted rear cover plate, the 9" does not.

One other thing to consider is that if you change gears above the 3.73's, you will need a new carrier (ADDED cost). There are numerous vendors like Randy's Ring & Pinion, DTS, and Bronco Graveyard. There's alot of info on the web on ways to strengthen or bulletproof either axle to eliminate the common problems, especially with the 8.8" axle.

Good Luck, JSM84

 

[351windsorbronco]

well i am pretty sure i have the 3.55's right now and i am not sure which rear end i have because i can not visit my truck right now. I have a holley 670 cfm street avenger carb, edelbrock performer intake an ISKY 262 supercam 302 camshaft, Windsor Jr. 180cc heads, Hedman Headers long tube, and probably somethin else i am forgetting, But that was just a geuss on the horsepower and torque i could be wrong, i have been towing my boat forever i even towed it up violently steep hills when my truck was stock, Now that i think of the rear end i probably have the 8.8

AS always BUILT FORD TOUGH

Happy motoring,

P.S. are you saying i should go with the 4.10:1's or would it even be worth it in horsepower vs. Money factors., How much more hp do you think it would get to the rear wheels, cause its probably got a good amount sitting at the flywheel and disapearing in the transfer case and in the auto trans.

 

[Justshootme84]

In my opinion, if you do indeed have 3.55 gears or 3.50 if it's a 9", you will not notice a very large or "perceptible" difference if you swap to 4.10's running a 31" tire. You can play around with some of the formulas to compare gear ratios. I think you're fairly close on your HP estimate with those mods, too.

 

[351windsorbronco]

In my opinion, if you do indeed have 3.55 gears or 3.50 if it's a 9", you will not notice a very large or "perceptible" difference if you swap to 4.10's running a 31" tire. You can play around with some of the formulas to compare gear ratios. I think you're fairly close on your HP estimate with those mods, too.

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ok well thanks for the info, it sounds like its not worth the 150 or 180+ dollars so i think i will keep what i have, thats cool i got a pretty powerful motor i really like it i redid it last summer and i thought it was just a pile i think the cam had a to big of a duration and lift and it felt like it was for a manual trans. So i tore it down about 2 weeks ago and rebuilt it, i like the feal of it now it takes off real nice and sounds like a BEAST with the 302 firing order

PS i was hoping you would tell me i had more hp than i thought