Here's something to think about: I had an 06 GT Stang with a 5 speed manual (3650 ?) backed by a 3.55 rear on 26-27" tires (the factory tires) First was nearly useless in normal driving, I frequently took off in 2nd instead of 1st. This is why Ford later went to a 3.27 gear in the later models. So your choice of 3.55 over 3.80 is a good one. First gear in that 06 was almost always hard to downshift into, you had to pop it into neutral and wait a few seconds for the snycros to slow down enough to mesh, (this is a function of the thin ATF fluid in these transmissions)otherwise it would grind everytime, which is very hard on these transmissions that lack brass blocker rings (snycros)
Mine is hard to hook up with 295's on the rear. These cars are almost like a pickup truck in this regard.
lol.. no doubt! while many love the look.. that typical long nosed short assed Ford styling has its pitfalls. Luckily, we're not the only one's fighting against its negative side effects. Which is why I've already invested hundreds of hours into just the logistics alone of heavier engine setback in my Comet. Keeping it cleaner and stealthier is the tougher part though.. or I'd have already broken out my buddies plasma cutter.
I run 4.11,s 28x10.50 Mickeys no issues with first gear car gets driven to work on nice days (60 mile round trip) and with slapper bars hooks well
I am unsure of the first gear ratio trans was supposed to be from a 91 mustang originally tires are sportsman pro's
To some people, deep first gears are something those of us who've been shiftin gears (18 wheelers for 36 years here) try to avoid. I can always spot the newbies to truckin when I hear them go thru 3-4 gears before they're moving 10 mph. If the motor's got the torque to get a vehicle moving without using them, I do so.
..... third Im running 2.95 first gear 26" tire and 4.11's. I dont always use first gear unless im in a hurry get off the line. usually, I go 2nd to 4th. 3rd is a waste unless Im merging onto the interstate.