Lowest 12 bolt series 4 gears?
 

Helping a friend with a 12 bolt, he's looking for the lowest series 4 gears he can get, 3.73 is as low as he can find, does anyone make 3.5? Guys around here seem to know of the hard to find items and he's having a hard time finding any lower so figured I'd ask here :)

I have some questions. You are asking for lower than a 3.73, but asking for a 3.5? A 3.5 is a higher gear ratio. 4.10 would be a lower gear ratio. When talking rear end gears, the higher the number the lower the gear ratio and visa versa. A 3.55 was a stock chevy 12 bolt ratio, it should not be hard to find. Also, what do you mean by series 4 gears? Can you clearify?

3.73 is the lowest you can go with a 4 series carrier. If you want to go lower you will have to change the carrier.

Ratios in bold are available in sets for use with a 3.90 and lower series carrier. Anything lower than 3.73 will require changing the carrier housing itself to a lower series.

2.73 OE GM
2.93 OE GM
3.08 OE GM, USGear, Percision, Richmond
3.31 OE GM
3.42 USGear, Percision, Richmond, Motive
3.55 OE GM, USGear, Percision, Richmond, Motive
**3.73 OE GM, USGear, Percision, Richmond, Motive
3.90 OE GM, USGear, Percision, Richmond, Motive
**4.10 OE GM, USGear, Percision, Richmond, Motive
4.30 USGear, Percision, Richmond, Motive
**4.56 OE GM, USGear, Percision, Richmond, Motive
**4.88 OE GM, USGear, Percision, Richmond, Motive
5.14 USGear, Percision, Richmond, Motive
5.38 USGear, Percision, Richmond
5.57 Percision, Richmond
6.00 Percision
6.14 Richmond

Thanks guys, thats the info he was given and found searching, always good to ask incase someone just came out with something...basically the 3.73 he has ordered is the best he's going to do without changing carriers :)