mine are 4.11s, u divide the number on teeth on the ring by the number of teeth on the pinion right? to get the gear ratio? if thats the way to tell then i do got 4.11s

 

4.11s here as well. But the same old sad story - they are stll in the garage.

 

Send them to me , I will install them and call you in the mornin to let you know how much I love em . No for real, get off yer but get em in and enjoy your new found grunt. Don't worry about traction you'll never have that with a stall anyway

 

You have a set of gears that are 37 and 9? This is news to me! I really didn't think they made 4.11's for our trucks. They're quite a bit stronger than 4.10's so this is kinda important. They don't make 4.33's do they? That would kick ***!
Are you sure they're Motive gears? They wouldn't happen to be PN G885410, because those are 4.10's. I'm not calling you a liar at all, I'm just surprised that they're straying from the factory ratios.

 

The difference between 3.90's and 4.10's is less than 100 rpm at 70 mph. The speed differential is less than 3mph between 3.90's and 4.10's.

I use 4.10's with a 28" tire and was revving 4800 rpm going thru the traps with a stock TC behond a Vortec 350 ad 4l60e trans.

If you want an ultimate track setup, 4.10's or 4.56's or whatever is going to allow you to trap at whatever rpm your peak hp occurs at.

For street roll on action, a higher gear might be the best for your setup.

A 275 45 20 is 29.6" tall, 4.56's could be used for the strip. 2535 rpm would get you 70 mph in OD when crusing. 4.10's 2275 rpm will give you 70 mph.

For serious track action, you cant really expect low gears and street radials to give you any traction at all, you will need some 15" rims ideally with full slicks for the track, just throw a floor jack in the bed with youyr slicks and bring a Johnson bar and socket, I can swap off my street tires and bolt on the slicks in 10 minutes easy. Then you dont burn off your street rubber and can get some really good traction.
I get used slicks from CASACAR roundy round racers, I use qualifing slicks that only have a 3 or 4 laps on them, they are almost brand new. I pay a case of beer or $20 for 2 of them. I run 28x8" slicks on a 7" rim or 29x10" slicks on my 15x10" rims.
With my L35 V6 S-10 stall converter I can cut 2.00 60's all day long.

in the past I have run 325/50/15 BFGoodrich Drag Radials, they hook awesome, are 28" tall with a 12" treadwidth, but are expensive and wear VERY quickly. Ideally they need quite a bit of heat, so this kills them in short order. But they do really hook well.

In the trucks, normal street radials are VERY difficult to get serious traction with, esp with a stall. The more sidewall height will give you more traction. A 20" rim with a 30" tall tire will not hook near as well as a 15" rim with the same 30" tall tire. The sidewall gives more increasing the contact patch with the pavement. 20" rims are heavy as well.

Gear for your purpose, and get some stickies, and enjoy the newfound acceleration.
peace
hog

 

I've got Motive 4.11's as well. I don't know the part number though. I know for sure that the box said 4.11 on it.

 

motive ratio chart

no experience with motive, but their website gives no indication of 4.11, but however if you search around you can find 4.11 motive gears advertised. Hmmmm

 

GM10-411 - 37:9 - listed as 4.10

http://www.motivegear.com/pages/catalogs/catalogs.htm

third catalog, page 32

 

Yeah that's the chart I looked at as well. I dunno? I'll take your guy's word for it, but if anyone finds some 4.33's let me know.

 

I think I'm just gunna keep my 4.10s, might as well if its only about a 100 rpm deifference then the 3.90s