Gears & Axles - 3.73 3.90 4.10 ?? th350 not a dd

hey guys in looking to do a gear swap on my car. i have th350 with 3600 stall. rest of my mods are on sig. i will be mainly running 1/8 mile, but would really like to finish the 1/4 without hitting the limiter. i have two sets of tires i have 26 tall and 28 tall tires. don't use the hyw much, when i do drive it. so hyw is out the question. im highly thinking 3.90 to be in-between but if i could go 4.10 would be nice. the car spins to 7k

thanks in advanced

i look on the stickies but there was all on a4 trans

Here is the tool that answers that question. I saw your 1/8 ET in your signature, but not your MPH. The estimated 1/4 mile MPH is what you will have to use to determine the ideal gear.

My mph at the 1/8 is 7.7 @92 mph 1.8 60ft

if you are putting them in the 10-bolt I would go with the 3.90's they are alot stronger than the 4.10s

You need a good guess of your 1/4 mile MPH, and an idea when your engine tops out RPM wise. Then you need to factor in the tire height. For lowest 1/4 mile ET you should be just above the power band in the traps. Like at your 2-3 shift point. There are all kinds of drag race calculators on the web. Google and try them until you find one you like.

Al 95 Z28 I have a 4.30 in mine with a 28" tall tire.

stock 10 bolt has stock 323 on it

how bad is it to run a spool on the street very lil street use

You need a good guess of your 1/4 mile MPH, and an idea when your engine tops out RPM wise. Then you need to factor in the tire height. For lowest 1/4 mile ET you should be just above the power band in the traps. Like at your 2-3 shift point. There are all kinds of drag race calculators on the web. Google and try them until you find one you like.

Al 95 Z28 I have a 4.30 in mine with a 28" tall tire.

i have the limiter at 7k i have two sets of tires 26 28 tall im really bad with them calculators

dialed some number is and this is what i got

1/8 Mile ET: 7.59
1/8 Mile Top End Speed: 87.74
Ideal Ratio: 5.73

dialed some number is and this is what i got

1/8 Mile ET: 7.59
1/8 Mile Top End Speed: 87.74
Ideal Ratio: 5.73


He wanted gears for the 1/4 mile:)

Spool on the street depends on what you comfortable with. I have a tubbed 73 Nova with a spool and it's a street car. Also has 4,89 gears. But I knew what to expect before I did it.

Al 95 Z28 S60 w/spool

i don't get this!! i might just go 3.90 and see what happens. i wanted to go the tallest gear possible and not run out of gear at the 1/4 with a 3 speed.

about the spool i read up on people braking there axles from the tires chirping when they turn. im guessing that's out of the question or were they wrong? the car will see lil street use ill only drive the car for one hole week just be cause of excitement the first week out, but then it would be from my house to the track and back. maybe a hangout here and there beach maybe once a month.

noone else can shim in ?

I say if you not trailering it dont use a spool. I have rode in vehicles that have spool and they suck !!! Idk why a good posi unit would not work.

When you're between your stock gears and going 4.10.....go 3.90. Especially since you're thinking about going from track to highway, but definitely look into strengthening the rear end with a 9" or 12 bolt.

When you're between your stock gears and going 4.10.....go 3.90. Especially since you're thinking about going from track to highway, but definitely look into strengthening the rear end with a 9" or 12 bolt.

thanks guys i went 3.90 i will be doing the swap today or tomorrow. i i have the hole car apart right now. im doing weight reduction, trans rebuild, cam swap, and gear. should have it up by Friday to take it to the 1/8mile this week end and see how she dose.

Good deal. Glad you've made a decision you should be happy with. Best of luck.

Good deal. Glad you've made a decision you should be happy with. Best of luck.

thanks man

thanks guys for ur help