So what happens if you keep the old /6 rear end after 360 swap?

[pettybludart]

Back in WW2 they used to put them in tanks also!Run over buildings they did!!

 

[goldduster360]

I run the 360/904 combo but my 904 was originally behind a 360, it has extra frictions and a larger low reverse band. I just replaced my 7-1/4 withthe 8-1/4 which was in the car for ten years after the 360 was installed, it was working just fine by the way. Tires were mostly 205 or 215 70 14's, nothing too sticky. Probably logged 12,000 miles on it that way.

That 8-1/4 looks like a dump truck rear end compared to the 7-1/4, nothing like increasing the unsprung weight of the vehicle. Oh well, I don't think it will break now for sure.

 

[74Dusterkid]

i have the december issue of mopar muscle and ther is a guy andy burleson running a 10.668 with an 8 1/4 ill post his stats

BLOCK: .030-inch over 340
CRANK: stock 3.31-inch stroke
RODS:eagle i-ibeam 6.123-inch
PISTONS:SRP 9.8:1
CAM: comp solid .540/.549-inch lift; 252/256 degrees duration at .050-inch lift
HEADS: edelbrock RPM ported by hughes engines
INDUCTION: victor 340 intake and carb shop 750 holley
EXHAUST: TTI headers with 3-inch pipe and flowmaster mufflers
ADD-ON: 150 shot of nitrous

TRANS: 727
CONVERTER: PTC 9 1/2 inch
SHIFTER: hurst promatic 2
VALVE BODY: stock

SUSPENSION

REAR: 8 1/4 with a strange spool and mono-leaf springs and cal-tracs
GEARS: 4.10
FRONT: factory k-frame with disc brakes
CAR WEIGHT: 3,300 lbs

BEST PASS

LAUNCH RPM: 4,000
60 FT: 1.60
SHIFT POINT: 7,200 !!!!
EIGHTH-MILE: 6.804 @ 102.83 MPH
QUARTER-MILE: 10.668 @ 126.39
* USING A 150 SHOT OF NITROUS

 

[mark_68_dart]

i know this is a little old,but i had to post this pic

that is my car with the old 7 1/4.it may have blown,but it lasted through 3 trips to the track and over 6000 miles with my 360.

 

[bignasty123]

in my valiant i had a 360 with 509 cam and it was strong and i beat the hell out of the 71/4 amd it never broke for two years i didnt hacve sticky tires either but it was fun

and if ur so incline weld the spider gears together and have a poor mans posi

but just my 2 cents i have had luck but u may not good luck

nate