Larry Dunlap

I now have a pretty well modded car, havent gone into the engine yet, but plans in the future for cam, etc. I should be running in the low 13s or high 12s

I just put in a street/strip TH350 tranny. I have the stock rear end, 10 bolt for a 91 Formula with 3.23 gears. I dont want to go to high on the gears, since I don't have an overdrive now, and I still want to street drive the car, or drive it to the track.

Ive got nittos, but am thinking about slicks for the track, as my recent mods have allowed the engine to surpass the tires again, traction is an issue in other words.

I know Ford 9" and Moser 9" are supposed to be good. What do you all think? Im thinking 3.42 or max 3.73 gears

mw66nova

iTrader: (13)

either 3.42's or 3.73's will work well, i have used both on the street with my 700r4. if it is a daily driver, then i say go with 3.42's but if it's more of a racer than 3.73's. the stock 10 bolt will hold up well with a good set of aftermarket axles and a powertrax lockright locker. i would also suggest a good rearend cover. if you ever consider spraying the motor or making more power than i would suggest going with an aftermarket housing like a 9" or a 12 bolt. also, 9bolts are very good but i don't know much about them. all i know is that they are stronger than our 10bolts.

Larry Dunlap

Well its not a daily driver, but its not a 700r4 either. The 700r4 has 4th gear overdrive, and this one, TH350 doesn't. It is more of a racer, but I do drive it on the street. Im must wondering if the 3.73 on the freeway in 3rd gear will significantly wear on the tranny. Iv got a tranny cooler and a larger fluid pan. What is that "locker", im not familiar with that. Ive just barely heard of it.

Blackroc86

I have a TH350 and 3.73 gears in my car. It is not the best for highway driving as the revs are up pretty good at 70 mph. I think your 3.23's or maybe 3.42's would be better for an occasional drag car.

MdFormula350

nitto drag radials should still hold pretty well. what suspension mods u have? sounds like u have enough engine just might need some well chosen suspension mods.

Larry Dunlap

running stock suspension. What suspension mods would give the the best bang for the buck? Im thinking Lower Control arms with relocation brackets and adjustable torque arm/crossmember

Hmm, yeah, youve got more motor (406cid) and more stall 3500 than me, I might be ok with 3.42

five7kid

iTrader: (14)

How far is it to the track? I drive the '57 to the track, but it's only about 8 miles and 65 mph. Runs a little over 3200 with 28" tires (I switch to the DOT slicks at the track).

Do the 10-bolt beef-ups (TGO tech article https://www.thirdgen.org/newdesign/t...nguprear.shtml , or CHP magazine http://www.chevyhiperformance.com/te...148_0207_bolt/ ), it should handle the task. Keys are 28 spline axles, support cover, and aftermarket axles.

(I'm biased towards AMSOIL lubes, otherwise I agree fully with the two articles... )

Larry Dunlap

The 1/8 mile track is only about 25 miles, but the 1/4 mile track is bout 80 to 90 miles. That is why I have never gone there, I always end up going to the 1/8 mile track. But Ireally want to go to Houston Raceway Park, 1/4mile, its supposed to be one of the best strips in the country. I guess I could get a trailer, I saw one for like $1500 with brakes and all. If I do that I may go whacky on the car though, haha

IHI

iTrader: (1)

I started out with a 3.08 gear set, right away went with the 3.42 for the first gear swap and used it behind the 700r4 and later the TH350. Since you to have the TH350 I'll stick to that. I run a 28" tall tire and with my crutch motor was consistent 1.80 60's and crossed the traps around 5K. Street drving at 60-65mph put me around the 2900-3000rpm mark on the hwy which is acceptable by any means and any motor. Think of all the cars out there before OD became standard running TH350/400 and gears in this range. I later switched to 3.73 at the end of last season when another rear end let go. This yeilded only about a 3-400rpm difference on the hwy putting me around the 34-3500 mark at 65mph and my 60' went into consistent high 1.7? and even dipped below the 1.75 mark a few times. Trap rpm raised to about 5500 with the 3.73 over 5000 with the 3.42's. Sadly this rear end let go faster than the other 2 and this one I even welded the tubes, and got the good preload cover. I was really happy with the 3.42's and they seemed to me as a great "all around" ratio for street driving and brackt racing with a barely showing up on the dyno hp numbers that this motor makes. Hope this helps out with real life numbers to mull over I should also note that my suspension has always been stock and I noticed zero gains/losses anywhere with the addition of the relocation brackets and tubular control arms. It may have a different effect of radial tired cars or radial drag slicks, but DOT slicks or all out race slicks I doubt any gains would be seen, as was MY case. Better add that before I get jumped about it.