well i have...
350 small block
twin t3/t4 hybrid turbos
turbo 350 tranny
and im looking for gears to go in a moser 9 inch

this car had a 2.8 v6 when i got it, well, im a guy so that just doesn't do it for me. i buy a crate 350 for it to transform it to a weekend warrier. then the twin turbos happen, i had a blind horsepower rage and ended up buying them and replacing the 700r4 with a performance built turbo TH350. now i have to get the gears this car started out as a 2.8 Daily Driver and is now starting to see the track in its future.(1/8 mile) this car is still street legal and when finished will still get to go brag on the weekends, but i also want to have gears that will hold up with the track. im thinking 4.11's for street/strip use. anything will be a help

thanks--joel

i say 3.73 i got them in my 82 with a th350 and with a 26in tall tire im turning 3k at 60

Turbo engines like to pull against a tall axle ratio, and with the added mph at the end of the track, and the modest rpm range that go with turbo'ing a crate engine, I'd say start with 3.50:1 gears and at least 31-spline axles.

Atilla is right on this one. There are still many factors in deciding an optimum rear gear ratio(cam size, tire height, converter stall, etc), but turbo motors need load to work well. I'd say probably now lower(numerically higher) than 3.50 .

probably taller, but 3.50s are easy to find, either new or used, cheap, and you gotta get a baseline before you can home in on the exact gear.
Finding a good used "chunk" already fitted with 3.50s and a 31-spline limited slip should be a matter of a 15 minute search online, and come in under $500. The same can be found at some junkyards, out of a truck or van, for $50, but you'll probably destroy it soon after getting a baseline.
Cars and vans came with 3.25:1s on 28 spline, and everything came with 3.00:1s on 28 spline, but 3.50:1 is the least gear Ford ever combined with 31 splines, as far as I know.