fwiw i had 410s in an lt1 car that trapped 116. i pulled a few 1.80 short times with'em and had lord only knows how many 1st-2nd-3rd whatever gear pulls. the car was on drag radials 24/7. no girdle. the abuse that car saw was ridiculous. even did a few 3-2 "upshifts" haha. it didn't break. i'm sure it would have had i kept it any longer. i sold it after breaking 2nd gear completely off the shaft.

 

Nice What brand gears were you running?

 

Oh trust me it goes sideways when I tell it to

 

richmond. i had a set of 373s (strange) in my stalled a4 ls1 car. it saw at least 100 1.65 or quicker short times @ 3600lbs. i'd guess maybe 350 track passes total before i sold it. it did have a girdle.

i think a lot of how long the gears last has to do with the install. the same guy did both of mine, neither made any noise or gave me a minute's trouble. come to think of it, the same guy rebuilt a friend's 10 bolt. his car went 10.7s @ 128+ (obviously not a hard 60') numerous times and honestly had more street time on it than track time. i know a4s are a lot easier on the gears, but making a 4k stall a4 car trap 128 (with das above 2k') @ 3500lbs is quite a bit of power.

 

i ran 3.90s in my nova and 4.10s in my camaro, it was pretty much the same

 

I got 4.10s and love it. Don't remember how it was before. My SS never sees the track. It's just a weekend cruiser and corner carver toy. Below 70mph in 6th gear, it lugs. To me, the car runs best above 70mph in 6th gear. With the 4.10s, I can get 28mph if I'm not on it too much.

 

Thanks for all the imput guys, does anyone know the actual difference in number of pinion and ring gear teeth between the 3.90 and 4.10? Also is anyone in here actually running or has ran a 390 on an fbody? Seems like all 410 guys.

 

Well I know it can be done, had a set of motive 373's in my last auto on a 4500 converter and that car had quite a few passes on it and some 1.5 60' passes at the track and it held up for a while. Eventually got noisy but I think the crush collar just started backing off or something because it got louder over time like a year and I just never looked into it then BOOM coming to a stop sign one day and about 5 mph it sounded like a shotgun going off. Broke 2-3 pinion teeth and 4-5 ring gear teeth off the damn thing. Was just coming to a stop!

 

Which is interesting...cause that basically means the 3.90 set will have thinner ring gear teeth. Kinda reverses some people's arguments on this site, lol.

 

I dont see how that can be right, I would think the one with more teeth would be the 4.10. Something isnt right there, no way the 3.90 has more ring and pinion gear teeth.

 

just looked in my Jegs catalog... 3.42/3.73/4.10 all use the same 41 teeth ring gear, it's the pinion that changes.

edit: also 2.73 and 4.56 ratios use a 41 tooth ring gear. BTW these are richmond gear sets I'm using as reference but they're all the same. The truth comes out about 'thinner ring gear teeth'!! They just use a bigger/smaller pinion gear to change the ratio. My old 3.42 pinion looks huge next to a 4.10 pinion

 

Hmm sounds right, does it specify number of pinion teeth? I remember the 273 in my other camaro looked massive compared next to the 373 I put in as well.

 

Yes, I'll put all the numbers listed on here...
2.73 41-15
3.08 40-13
3.23 42-13
3.42 41-12
3.73 41-11
4.10 41-10
4.56 41-9

 

I'm a bit confused now, shouldnt the higher gear ratio have more teeth on the gear?

 

I've had both and I like the 3.90's better. They are stronger, I broke 2 sets of 4.10s with out even haveing a dr on the car. With dr's on the car I now break axles but not r&p's anymore......not to mention the car is faster with the 3.90's.

With 4.10's the car just seemed to be reving and not really applieing the tq.

 

I used to think the same way but if you visualize changing the pinion it starts to make sense. Same ring gear, with a pinion with 12 teeth, 1 full turn moves the ring gear X amount... Same ring gear with smaller 10 tooth pinion, 1 full turn moves the ring gear Y amount. X is greater than Y, so your 'Y' pinion gets you the numerically higher ratio. Hope that made any sense.

 

Ok...so if these are richmond gears..

2.73 15-41
3.08 13-40
3.23 13-42
3.42 12-41
3.73 11-41
3.90 11-43 (Motive)
4.10 10-41
4.56 09-41

and motive is...

3.90 11-43
4.10 10-41

I see the 2 4.10's are the same but the whole 390 and # of gear thing still confuses me, if the the sets listed above are correct (I added the motive 390 in there with the richmonds) then isnt the 390 actually smaller then the 373??

 

Go with 4.10s and don't look back. If you have the know-how run the solid spacer instead of the crush sleeve. Gear failures in the rear ends of these cars are 99% of the time due to teeth mis-alignment, and not because of too much horsepower.

If you know how to drive the car like you have a rear made of glass, you should have no problem even pulling decent 60's. My buddies Camaro has pulled a few 1.80 60's with a stock rear besides the 4.10 gears and DD's it on those same DR's. It's more or less about the driver/installation than anything.

If you really think your going to find strength in any gear ratio 10 bolt your kidding yourself.

 

There is also a 9-37 gear set. That's 4.11 for you no math types . It's the stronger of the 4. gears. The ring gear teeth are thicker and don't bust as easily. The size of the pinion diameter changes even if there are the same amount of teeth.

 

In my opinion 3.90 is the best all around gear for the 6 speed cars. I have had 3.73, 3.90, and 4.10. I hated the 4.10 on the street. Might as well not even have 1st gear. I have 3.90 now and love it. And, yes you can tell the difference between 4.10 and 3.90.