as it turns out, on my '86 LG4 i have 3.23 rear gears on an auto instead of the 2.73 it's supposed to come with.

what's the difference in terms of performance? and will it be good for a >350hp engine?

 

If you have a set of 3.23's in the car now, and it is a posi, I would leave them alone. They should be just fine for a mild 350 (idle to 5500) with say a ZZ4 cam, stock heads, street tires, etc. I installed a 3.73 into my LG-4 T/A and it was too much for the lil 305. I would have had to change the intake and intalled headers to get the engine rpm's up. Then it would have been fine. But I was going to install the 355 so it didn't matter.

As for performance, the car launched harder out of the whole, it was easier to do burn-outs, but the overall quarter mile time didn't feel like it changed much, and the 305 tried to over-rev too easy. It just boiled down to a 3.73 being too much gear for the stock LG-4.

 

i was told posi isn't good for snow/ice driving

 

Depends on who you talk to... open diff is easier to control for a novice driver. If you take any kind of turn in snow or ice, both wheels will turn and one WILL slip which will send you into a fishtail. However, if you know about that you can anticipate it and even use it to your advantage. I know I wouldn;t have been able to get out of my parking spot last year if I still had an open diff, but the posi got me out.