Poll-which rear end?

[DUSTPAN340]

I went with the 3.91 I ran them with my 416 with 4 speed
Now I took out the 4 speed and put in a 727 with a 242 first gear and a 142 second
And kept the 3. 91 sure grip with a 275/50/17 tire in back about, 28 tall highway is no fun but on the street she is a blast but I think the gas Guage moves faster then the tach lol lol

 

[Captainkirk]

Well, so far it's 44-14 for the 3.91 with the majority vote going toward using the rear out of the Li'l Red Minx.
We'll see how long we can hold the lead here for rubber-burnin' rear!:burnout:

 

[Captainkirk]

Well, now that I know the difference between a cone and clutch diff, I have to figure out if each is a cone. Pretty much positive the 3.55 is untouched from the factory, but the 3.91 is out of a Mr. Norm's car, so it's 'possible' that a clutch pumpkin might have been installed, though not likely. (The engine did have the cam and 13:1 pistons installed). Guess the only way to find out is to 'carve the pumpkin'. Anything I should know bout pulling the axles and opening it up?

 

[dirty white boy]

had a 71 duster 4speed 3:91 car back in the 90s, had 750 mechanical carb,..eddy ld340 intake,..X heads milled to 12 to 1 with flat tops,...crane 500 lift cam,...ol car was a beast,..came outta the hole like it had N.A.S.A on the quarter panels an pulled hard threw all 4 gears,..was a blast to drive round town,..cruise nights!! to quick for strip without a cage...but was turning lotta rpm's on the highway,...but i wouldn't have wanted it any different...wished id keept it to this day,...had 1800 bucks in it,..matching numbers with no rust at all...dumb *** me traded it for a 55 chevy project...

 

[blewbyoutobad]

I run 4:30's in the Valiant with a 27" tire. 55mph at 3100rpm. Never drive it over 50 miles anywhere so it doesn't matter. I have more time to enjoy driving since I always get there last with the car club. I've run higher gears, lower number and the roller cam just doesn't work like it does with the 4:30's. Go 3:91's and with a 4 speed it will be a lot of fun to drive.

 

[rbdart]

3.55 with auto...definitely 3.91's with 4spd... so 3.91's would be my choice..just chk out whichever pig u decide to go with prior to installation...wear pattern,bearings,pinion nut torqued for sure and stuff it in and rip away...