Alright,the car and mods are in the sig. right now it has 323 gears and i was wondering if a 373 would be alright for it. obviously the days of highway racing will be over but since i've switched from the 700 to the th350 it needs more down low. but i'm not sure if the 373's will be to much, any opinions will be appreciated.
Derrick

 

i was going to do this to my v6 before i decided to go ahead and get another car (still searching)
anyways, since you're jumping 2 gear sizes you'll definately notice a difference, and since it's a v8, a really good difference.
only downside is a little worse gas mileage (not much, maybe 1-3 mpg) and like you said, highway isnt going to be too great (but not terrible either)
i'd say go with it, and i'm not sure if your car came with posi or not, but if it didnt you need to add that too. trust me, i know about 1 tire friers

 

i have 3.73's in my 350 (headers, shift kit) and i love it. I havent raced the car since i bought it but i think im probably running real low 14's if not hi 13's

 

thanks i'll prob go ahead and do it. my car is posi, and yes that's a nice addition. i guess my car is a freak b/c it ran mid 14's with the 700r4. the gears should drop it even more.
thanks
Derrick

 

how much are 3.73 gears? and how much would it be to get it installed?

What do i have right now? I got a stock 86 IROC.

 

Pancho

 

3.73's behind a TH350? That's not just saying goodbye to highway racing, that's saying goodbye to highway period. 3.73's kill the top end of 700-R4 cars; without the overdrive you'll be turning like 4000rpm at 70mph. And with a TPI setup you don't make much power above 4-5k anyway, so plan on topping out around 80 and getting run over by truckers.

My $.02

 

Also 3.73's are probably going to HURT your 1/4 times, because with the 2400 stall you're gonna be out of the powerband before the trans has time to shift. Go 3.42 if you want, but no higher.

 

Who You Talkin To

 

Talkin to Stang....


Kuruption you'd probably be alright because you still have an overdrive tranny.

 

true about highway, but ever since i switched to the th350 it just doesnt seem like the same out of the hole even with the 2400 stall(which really stalls at about 2000). i know the gearing is diff between the th350 and the 700r, but i figured the stall would help. used to i out launched all the lt1s i raced and now i'm afraid they'll get me out of the hole. so i don't know what to do.

 

I have 3.73 in my rear end without a problem. I drive the car all over creation and get 300 miles to a tank of gas cruising and 200 in the city.

 

Yeah but you also have a 4-speed tranny. The TH350's top gear is the same ratio as your 3rd.


Stang...I don't know what to tell you about your launches man. The 700-R4 has a VERY deep 1st gear that you lost when you went to the TH350. It also has a .62 overdrive which lets you run lower gears and maintain highway capabilites (you gave that up too.) I personally wouldn't put a TH350 or TH400 into anything but a dedicated drag car or 4x4....but since you already did you'll just have to live with it. The good news is, the TH350 is very stout and you don't have to worry about breaking it.....stick a 150 shot in her and see how THAT helps you pull LT1's.

 

that sounds like a plan. i think the ignition module might have something to do with the slugish launches also. i know the tranny will hold the 150 shot, but what about the engine? it has 100,000 miles on it. The old man i bought it from was the original owner and supposedly he never put it over 75 mph. so it's in good shape.

 

It should hold up to a 100-150, but I wouldn't go any higher than that. It would be a good idea to pull a valve cover just to see how clean the heads are....that's a pretty decent indication of whether or not the engine has been taken care of.