Anybody got a set of factory gears laying around from an 8.8 say 3.08's or 3.55's somthing like that? I am starting to get some slack in my 8.8 and whenever I rebuild it I want to upgrade to slightly lower gears I have 2.72's (i think..) And I want to upgrade to a LS instead of an open diff. I figured between everyones upgrades and such somone has a set of factory gears for an 8.8 and I know several people have mentioned having LS unit. Its a daily driver so I dont need 4.11 or anything like that I just think that a slightly lower ratio wouldn't really hurt my mileage and would be alot easier on the clutch when pulling.

Check your Door codes and make sure you don't have 3.08s already. I have the TTB pumpkin in my parts truck for the 3.08s It might be a bear to get in and remove though.

Checked my door codes this is what I got.

133 f154 db4 m 12n l bu



12n being the axle code which isn't listed on the site? wonder what the heck it is.. I always assumed that i had 2.72's because I knew they were available and It seems alot higher geared than 3.08 considering I can burry the speedo in 3rd gear.

2k @ 75 is what my 150 runs with 308s and the stock 215 tires. You could do the jack up and spin the tire trick to find the ratio.
I wouldnt mind teh 308s if i had creeper but the stupid 4 spd has OD insted. pita pulling out with a trailer. At least the 300 can pull at low rpms. [img]images/graemlins/cool.gif[/img]

Hmm. Perhaps I do have 3.08's I am running 237/75r15's. Reverse is my main bitch. Seems like reverse is a higher gear than 1st and it will idle in reverse at what seems like 20+ mph. 99.9% of the time that I am backing up I have to slip the hell out of the clutch. I have the ZF 5-speed. 4th gear in my 76 is lower than my 3rd gear! In it I run about 2900 at 60mph! in 4th! Thats 4.56 gears and short tires for you.

I would think, unless you did a swap that you have the Mazda 5sp and not the ZF unless this is a 250 or 350 truck we are talking about and I would doubt it came with 3.08s.

Second your 76 is a 4 speed with fourth being 1:1 and the 5sp being a 1.49 (1.42 for the ZF) for third gear so unless you are talking about final gear ratio then......

Hmm, if u have the mazda 5 spd, your OD would be .8, mine is .71, so u might have the 273s. If you had the zf it would have granny 1st adn reverse.
Use 4th (direct) gear, and check rpms, this will make it constant insted of havig different OD ratios.
If your truck came with 235s stock, at 2K with 273s in 4th gear it shoud go about 62
If it has 308s @ 2k it should run about 55

Ever figurer out what gears ya got? I found junkyard 8.8s with 3.55s for $50 around here [img]images/graemlins/cool.gif[/img]

Hmmmm. eveyrthing i have looked at doesen't list my axle id. I still am thinking 2.72's but am not for sure. I will post again when I find out.

Code 12 is 2.73 ratio. If you pull your fill plug and look at the edge of the ring gear, you should find "2.73" or "11 30" stamped into it.