I am looking at building a project car ~3,200lbs that will be running an LS1 stock to mild mods. Will 4.10 gears behind a T56 be too much? Anyone running a setup like this on the street? What kinda MPG are you getting city/hwy? Is 1st gear usable at all?

 

Are putting this in an fbody or another chassis? from what ive read for fbodies, 4.10s are the way to go on the street. your gas mileage will still be good because of the deep 6th gear. i think its around 2k at 70mph. people say that 1st gear is worthless though unless you got good tires and suspension.

 

4.10s in every manual fbody except 93. 3.73's for the autos and FI's

 

looking to put this setup in a 1980 malibu....but looking for an LS1/T56 combo.

 

Absolutely it's streetable!! Heck, I ran 4.10's behind an A4!! As of tomorrow, I'll have 3.90's in my car behind the T56, but until now, it's had 3.23's, and they are way too high of a ratio for the 6-speed . 6th gear is pretty much useless!

Sounds like a neat project ... good luck with it .

 

3.90's? That isn't for the stock 10 bolt is it? I've been thinnking that 3.90 would be a great compromise for me, but haven't found a place that sells them for the 7.5".

 

^ ^ yes, Motive now makes 3.90's for the factory 10-bolt . I think they just started making them about ~1 year ago. I bought them through a local speed shop, but I'm pretty sure I've seen them listed in a couple of this site's vendors' catalogues .

... the only "problem" with them is that I "thought" the tooth count on the gears was going to be 39/10 (compared to say, 41/10 for 4.10's) which would make each of the ring gear teeth a little thicker. HOWEVER, they are in fact 43/11 (actually works out to 3.91's ) ... but at least the pinion is slightly larger than the 10-tooth pinion of 4.10's, which is what broke in my old ones, so hey, maybe these will actually be better?!!?!?!

Edit: I originally said Moser made the 3.90's, but I meant to say Motive!! ... oops!

 

Ya, thats why I'll stay away from 4.10s.
Plus I do like cuising at 80 w/low RPM. I may just go 3.73. Not much of a step from 3.42 but it is some.

 

Keep us posted on how those feel I was looking into getting that ratio when they came out last year, but have been lagging because I don't know if install ($500+) is worth it as opposed to going 12 bolt or Dana. If it's a noticeable difference above the stock 3.42s I just might go ahead and drop some cash.

 

why on 3.73's in a A4?

 

I did a bit of a write-up on them in the Drivetrain Forum (link).

Putting money into a 10-bolt is sort of subjective. On one hand, lots of people will say DON'T, and just save up for the 12-bolt, etc., but on the other hand, when a gear set is only a couple hundred bucks, that's a lot cheaper than a couple THOUSAND for the complete new diff . I think you'd notice a nice difference from 3.42's --> 3.90's/4.10's .

Because EVERYBODY says to only go as high as 3.73's behind the A4 . Pansies!! I ran A4 w/4.10's for 2 years, and would have no problem doing so again. I also had 3.73's, so I know the difference.

 

lol, I used to run 4.11's behind my TH350 with a 10 converter. 3500 RPM going 70 or 75 mph gets old.

 

I had the 4.10's on my M6 and they were perfect! about 2300 rpm's at 70mph in 6th gear. My only regret was getting richmond gears - they whined so damn lound on the decel that after a while I got pissed off just driving the car. DO NOT GET RICHMOND GEARS! I here the motive gears are quiet like the stockers.

 

I think my M6 with 3:73's does 80mph at 2000 rpm's. I love it!