8 1/4 rear

[volare360]

first off
am I correct in thinking a 77 volare 360 would have a 8 1/4 rear?
how do I tell-# of bolts on cover?

now for the info
how are these rears
I plan on 318,mild maybe 300 HP if I am lucky but I am looking at a 4 gear-no slicks,just street,couple times at track

I want 3.5-3.7 gears and a posi
at least that is the plan
worth it?(I already have the rear)

are parts inexpensive?
Posi?

[volare360]

BTW

the 4 gear is a non OD and a hurst shifter

could see a bit of pounding

[71Dodger]

I have a 71 Charger w/ a 318 and a 8 1/4 rearend. One sure way to identify your part is to see if the diff. cover removes from the back of the unit. You can also tell by the 10 bolts in a circular pattern. I believe that info is accurate.

[dwayne penner]

A volare could have a 7 1/4 rear or a 8 1/4 rear. I think all the 360 cars had 8 1/4. Pretty easy to tell, the 7 has an octagonish shape to is rear cover, while the 8 is an oval layed on its side.

If your worried about srtength a 8 3/4 from a late 60's early 70's b body is almost the same dimentions. the spring pads are about 1/2 diffrent, you can bow out the rear leafs 1/4" on each side or relocate the spring pads, you will also need to shorted your drive shaft and get the b body shock mounts, or modify the existing iso mounts.

[dansdart]

Quit worrying about that 8 1/4. I have one under my Dart Sport. I run a 325 horse 360, 833 od. 26 inch slicks and 3:91 gears with a sure grip. I have raced it for two years at least once a month. I figure I have at least 170 to 200 runs on this combo and it gives me no trouble. You are not going to hurt it with the use of a little smarts. I think it is the old arguement with Chevy's 10 bolt or 12.
Most Chevy 10 bolt rears are 8.25 in. Now the next time your at the drags look under the Chevy's and see how many are running ten bolt rears. You may be surprized. Use the one you have and enjoy yourself. I run altitude adjusted 13.5's and I shift it at 5800. So you can see I am not taking it easy on this rear.

[volare360]

thax guys

I was just thinking I have a /6 car sitting,all I have to do is look and if it is different then I will be a 8 1/4

I will be putting in the bigger rear,I just need to get gears now

[Tim_K]

That 8-1/4" axle should be ok for you. I have a '79 Aspen R/T 360-4 that is currently running 14.6's at 93 mph. I rebuilt a sure-grip and put 3.90 gears in the axle. To be on the safe side, I pulled an 8-1/4 axle out of a /6 powered Volare station wagon, and put the 3.90 sure grip in that one. With a /6, the axle shafts were never stressed hard. I kept the original 2.71 axle all in one piece.
Moser can make stronger axles for the 8-1/4 if you think you need them. And I think that late model Dodge truck 8-1/4's have a 29 spline axle instead of 27. Swap in the newer size sure grip, order some custom Moser axles, and you're set for 12's!

I know of a couple of 2 ton B-bodies at the local dragstrip. One has 3.90 open gears and slicks and runs 14's ('73 Satellite 360). The other has 3.90 sure-grip and runs low 13's('71 Coronet 360). Both guys say they've never had an axle problem.

[Keith]

What is the weak link of the 8 1/4? Can they be made stronger? I'm just curious in case I need that info in the future.

[A990]

Cheapest and quickest thing is to use ARP bolts. I've never ran this rear, but everyone I've talked to say they are bulletproof for what they are

[Sport]

Keith, I would like too know the were they break also. I just might find out though because I have been using one behind my 440 dart sport with a4000 stall 391 gear. that runs 10.9,s@ 1.54 60 ft. Looking at the one I have sitting on my bench the weakest link would seem to be the cross shaft trough the spider gears or the housing that holds the spider gears. The caps look heavy duty as do the spider gears themselves. Arp bolts are a good Idea ,and make sure you dont over tighten. I did this once when I was young, I thought the tighter the better, the first time I launched the bolt heads popped like dandilions. Took out a ford 9". My 8.25 has over 160 passes on it with the440. Going to tear it down this winter and see how its holding up. Sport!