T5 rear gears... what to use, where to get them

Currently I have 3.00:1 rear gears and am learning that I will have to goto a taller gear when I install my T5 which is a "249" code with a 2.95 first and a 0.63 final gear. I found a calculator that I can input all the gears and get a chart of RPM at differant speeds... and I found that 3.55, and 3.80 would give me some good balance, even 4.11's would place at about where I am at now with the 3.00's and my c4... what do you guys run? this is a street driver not a drag racer, 289 with about 300hp, I have the stock 8" rear end open differential.

where can I get a good deal on gears? anybody have extras? I would also like to goto a limited slip or locker, not a always on type... I forget the proper terms, sorry. where can I get deals on limited slips? I've tried local junk yards for other things and they so far would cost the same as what I find online. and I can't even find a good yard in the phoenix area that has some fords with parts I can use.

I'll appreciate any and all info. thank you.

 

3.55/3.80 is a good choice for a t5 equipped street car.New ring/pinions are readily available through Jegs/Summit.If you can find some old v6 Mustang toos or v6 Pintos they came with 3.40/3.55 gears.L/S or posi type units kinda hard to find used,kinda pricey new.

 

go to Summit and look at the Summit Racing brand gears. perfect choice for just about any street machine. im beating back and forth between the 3.55 and 3.80 choice myself. im just not sure what i wanna run yet, but i think ill end up with 3.55's since it'll give me better off the line than i have now (3.00's like yourself) and still get over 22 mpg on the highway

 

I agree on the 3.55 and 3.80 gears. I would not go any higher, especially with a carbureted engine.

Tim is correct on the Mustang II's and V-6 Pinto wagons.

Typically the V-6 4 speed Mustang II's will have these gears.

1974-75 Mustang II 3.55 open - code G, 3.55 locking - code X.

1976 Mustang II 3.55 open - code 7, 3.55 locking - code P.

Pinto's likely have the same door code for the axles, but don't hold me to it.

Stay with a fairly tall rear tire too.

 

We have 3.73 gears with both cars (2.95 and 3.35) 26" tires. I have 3.40 on the Mustang (3.35 first) 24.5" tires they all work great. Running around 2 grand on the freeway.

 

right now I'm running 255/60r15's which are 27" tall... if I got some gears would I need a full install kit? I was looking at this one on summit;
http://store.summitracing.com/partdetail.asp?part=RMG-8310151
but I guess I would have to get in there to see what I would actually need... how do I find out if I need the bearings? thanks.

 

If you pull the chunk apart to install gears/posi its cheap insurance to put new bearings in it as well.

 

My dad's '95 Mustang has 3.73's with a T5Z and I think it's all around about perfect. Great acceleration around town and it cruises 80 mph down the interstate no problem.

 

I am certainly leaning toward the 3.80's but I still can't completely dismiss the 3.50's and how they would behave with my setup? T5z, 27" tires although I might goto 26" tire... still trying to find good size tires that will fit all the way around without a problem. I have alot of differant subjects that would probably require there own threads but are all linked to this project...
I would like to hear some people who have used to above setup (trans and gears) and how they behave? particularly how much you have to drag the clutch to get it moving in the first place, and rpm at 75mph or so... I found a good looking calculator but it's on a F-body site http://www.f-body.org/gears/ but I would think it would work just the same. I'm just to damn inconcisive... Anyway thanks again.

 

I have 3:73ls 8.8, and I'm thinking of stepping up to 4:10

 

I'd go with 3.80. 3.55 just doesn't do it for me. 4.11 is too much for a street car. I say that because you're shifting into 2nd almost instantly after letting the clutch out in first. Had a set of 4.10's in a Mustang SVO once. Just as soon as you're letting the clutch out, you're almost pushing the clutch back in to go into 2nd. First is useless. Worse with shorter rear tires. But it does make for a cool 1-2-3 burnout, though

 

on my old fox body mustang i used to have i had 3.73s when i fist got it. it was a stock motor with exhast. it had a 27" tire. it was great. i didnt have to drag the clutch at all. i gear cars for a livng. i realy like the t-5 equiped cars with 3.73s. if somebody is really worried about gas milage i will put 3.55s in just to please the customer. i belive that the difference in gas milage between the two ratios in minimal and there is a noticeable difference in acceleration. the last unknow factor here is what is your motor built like. if its stock its going to have a relitive low power band, lower than the efi 5.0 and if thats the case then maybe 3.55s will be beter but if you have a 4 bbl carb and exhast then i would go with the 3.80s.

 

My engine is setup for a 1500-6500 rpm band... 289cu/in bored 0.030 over giving me 293cu/in, 4bbl carb w/edelbrock performer rpm air-gap intake, headers, dual 2-1/2" exhaust, 280 duration cam .500 lift, 1.84 intake 1.46 exhaust valves, 255/60r15 rear tires...

 

i say go with the 3.80s

 

this is my set up;c4 trans...2000 stall tci converter... traction lok 3.80... 295x50x15... 0n 15x8 4" BS... 55mph is 2500rpm... very very pleased with this set up for the street... my next set up will be a CR toploader,V-gate, 9 inch detriot locker with 4.30 gear... later on the Gearvender overdrive!!! BTW to the OP...if you are going to spend the money go with the 3.80 LSD and have fun...good luk