What size gears would ya'll recommend for a 9" rear?

 

ok first we need to know whats your setup, what kind of vehicle, engine, tranny and what gears do you have now? Also what are you gonna be using it for, towing, racing, etc...

 

well i found a set of 3.55 gears and a set of 3.73 gears on ebay, which ones should i get? the 3.55 is probobly better all around, but whats your opinion?

 

ok are they just the gears or the whole housing? Also you gonna do any towing and if so how much? Or are you more concerned about gas mileage, 3.55 is just fine with towing with excellent gas mileage, 3.73 is a little better for towing with the expense of using more gas. I like the 3.55's in my truck it has more than enough get up and go. But just compare the cost, if you can get the 3.73's cheaper and don't mind the extra gas you'd be using you could go with those. It's easier for you being 2wd you can just swap the rears. I don't really know much about 3.73's I've never had them, maybe you could find someone thats used them. I just hate to be giving you advice and it ends up being the wrong advice.

 

yea i was leanin towards the 3.55's, i use the truck for daily transportation to and from school and wherever else, and i just need some more get up and go power for the highway, i tow every now and then but its not like im pullin a horse trailer or somethin so the 3.55's should be fine.
I ran it in 4th today at about 55 to 60mph down the highway and it definitly had alought better power and i didnt lose 10mph goin up hills. Is this good for my engine though?

 

4th gear is real good for going up hills as long as your not loosing speed. You'd be lugging the engine if your in 5th. All overdrive is good for is mainly flat road and downgrades. Sounds like to me 3.55's will do you just fine. I towed a little today and I use 4th gear since it's 1:1 ratio and at 50mph I'm taching 2,000 rpms. So basically 50mph in fourth is the same as 60mph in 5th gear, should be the same mpg. I think 55mph is 1750 rpms with the 31x10.50's. The 300 doesn't make any power after 3500 rpms, so basically all you'd be doing is making noise and wasting gas.

 

Future mods include,
Hedman 6 to 1 Header
Offy 4-bbl intake mani
Holley 390 4-bbl.
Automatic C4 tranny?
4" Suspension lift.


I use it for daily driving, hauling, and possibly towing in the somewhat near future. Thinking about a set of 3.83's? Wouldn't be for a while though.

 

the 3.55 gears i found on ebay are out of an explorer with an 8.8 that was hit in the front, do you think i could trust these? The guy only wants $25 for um, but how much do ya think it would cost me to get them installed?

 

sounds like you'd be using around a 35 series tire, I'd at least reccommend 4.10, even though with the lower gearing that big tire will make up for it.


most times with the explorers they didn't do a lot of towing or any serious hauling and most have the 3.55 I had a 91 4wd that had the same gearing. If the gears didn't have too many miles on them and there isn't any chipped/cracked teeth you should be ok. I don't knw how much it would cost to get just the set of gears installed but I know it's around $600 to get the whole rear rebuilt. I'm gonna put a zf in mine first before I decide on any gear changes.

 

Thats what I was figuring on was the 4.10 gears. Haven't delved to far into really looking for a good price yet though, just something I wanted to keep in mind for future use.

On another note, I was thinking about putting in a Detroit Locker in the rear aswell. I believe I read it will give me posi traction at lower speeds, until I reach about 25-30 miles an hour. Would this be a good idea, for me? Or a bad idea.

 

if you do a lot of offroading and drive in the snow. I think it would be a great idea, I've heard that lockers can be noisy when locking/unlocking. I've looked at the powertrax ones since I have open gears. I don't do any offroading but sometimes the winters gets pretty bad here, some years we hardly get any snow and some we get a few feet.

 

I can throughly relate. I am just east of you? I'm in Southern MD. I know the weather around can get kinda hectic. Never heard about them being noisy though. But then, I am still relatively new to the Truck world. I really do miss my sports car.

Thanks for the advice though.