Not ridiculous at all - we have people here putting 4.88's in.

 

I am running the Ford Racing Performance Parts 4.10 w/ a factory limited slip. It works well enough for me with 35" tires.

 

4.56's are way too much for 2WD with street wheels and tires. His engine would be screaming at high way speeds.

 

Maybe so, but it sure sounds like he wants to burn rubber....................

 

4.10's will burn rubber with all the mods he's done to his truck, and as long as he keeps those street tires.

 

Why would 4.10's burn rubber and his 3.73's not? There's not THAT big a difference.

 

I think 4.56 would be ridiculous with my size tires. if i had 35s i'd be down for 4.88s. it sounds like 4.10 would be good, but 4.30 is better (and probably the max i can go with still being a daily driver).
AND...
I was quoted today $475 for the install of the ring and pinion and the differential. he would also supply the oil and gaskets. i would supply the gears, install kit, and differential. Does this price sound reasonable?
and for all those who have been wondering about how to properly break in a new set of gears(YES there IS a break in period) here it is: First 100 miles(no highway driving), next 400 miles(limited highway driving - like 7-8 miles at a time), during these first 500 miles drive her real easy like, next N miles(drive the **** out of it!). this is coming from a guy 25 years in the gear business. i guess i'd trust him.
he also recommended the Auburn Pro series over the Detroit True Trac. he said the true trac has spider gears that are prone to break.

 

I'm pretty sure i'm gonna go with FRPP 4.30 gear. i have been reading on mustang forums hat the ford gears are cut by Motive and known to produce gear whine. can you say this of your set?