I know this has probably been covered 10,000 times but. . . 69 383 Super Bee w/ original 3:91. Putting together a street package to hopefully dip in the high 11's. 500ci (4.15 stroke) running beefed, but stock geared 727. 28 inch tires. This car will be 95% street use, not interstate. I figure the 3:91 will just be too much. Is the 3:55 too much of a torque killer? I'm thinking the extra engine power will translate into speed. How much seat of the pants difference in the two. My converter has yet to be determined. Thanks!

Depends on quite a few things.

What exactly is your new combo?

with all street use,i would stay with the 3.91,s. i use 4.10,s in my 580" 70 charger,and love them.it,s only a street car too.

With the right 500 cube combo, high 11's should be a slam dunk with 3.23's and then you could drive it anywhere. Converter will be key.

Kevin

You also don't say how much freeway cruising you do. If a significant portion of your driving is over say 65mph the 3.91's will grow tiresome.
If on the other hand your mostly a city brawler then they will be fun!

Stay with the 3.91 gear, theres only about a 4% differance between them. Not worth the money or time.

Taller hides for strasse use and stick with the 3.91's.

3.91'S with a 500" motor? it should FRY the tires thru 1st. and 2nd unless it is a really weak motor. imo

I have a pump gas 512 low deck stroker motor I put in my 1971 Duster, it ran mid tens at 128.+ MPH with 4.10, 3.91 and 3.73 gears in the 8 3/4 with the same converter The percent of differences between the 3.73 to the 4.10 is right at 10.%(4.10 divided into 3.73 =.9097 the way my calculator figures) Big C.I. motors develop a lot of torque, torque spins the tires, not HP The differences between the 3.55 and the 3.91 is right at 9.2 % on the starting line and in high gear, with your size tires (I run 315x60x15 MT ET Street Radials, 30 inches tall) I would try the 3.91 first seeing as there in the car and if it spins or revs to much switch to the 3.55 as long as you don't have them now. If you have both try the ones in the car first My car didn't really know the difference between all three sets except in high gear, the car seem to spend a lot more time in high gear with the 3.73 The time slips where almost identicle EDIT: Make surew and buy a really good, custom built converter for your car, don't skimp