Mike,
The Pro Chamber was a breeze to install. Combined w/ the Mac cat-back, they sounded awesome together. It had a nice low rumble and was pretty loud, but not like my Cobra was w/an offroad H and 2-chamber flows. That was really loud, so off the o/r went.
As far as the gears go, 3.73's felt pretty good in my GT. They say they are comparable to the 4.10's on the Cobra. Well, I stepped up from 4.10's to 4.56's in the Cobra, and love it. So, maybe 4.10's in your Bullit may be comparable to my 4.56's.
Let me know if you have any more questions and good luck in your modding venture.
Welcome to the Mod motor world!
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T-Bones 1997 Cobra#6342 born 6-11-97
Wht/blk, Pro 5.0,FRPP 4.56's, aluminum driveshaft, FRPP throttle body, C&L 80mm MAF, K&N, Steeda U/D pulleys, Steeda timing adjuster, Flowmasters, s/f connectors, FRPP pro springs, BBK caster/cambers.
My old 96GT