Dave E

Guys,
My brother and I are building a 1970 Challenger street/strip car. We have a mild to medium built 383 in the works a Tremec 5 speed manual trans and are wanting to know what would you guys recommend for a rearend. We are wanting to weigh in cost, availability of parts, functionality, and of course reliability. We are considering a detroit style locker as well. Any advice would be appreciated.

As a side note I have dealt with the 8-3/4 mopar before and my biggest beef with it is the fact that there are 3 or 4 different versions with different yokes and bearings. So annoying to try to make sure you have the right parts for what you have. So that being said... HELP!!!

TVLynn

I would go with a 3.55 gear and maybe a low gear set ? in the Tremec

RacerHog

Dana or a 9" is my preference.....

Coronet 500

I agree with Bob, when many start a drag build the plan changes because speed is addictive.

First it's HP then higher stall then trans brake then nitrous then HP rehab with a broken axle.

I know a couple of guys that started with 8.75's ended up with $2000 dollars into each one and still breaking them. Dana 60 will take whatever engine the car may have.

Archer

Dave -

Normally a 3.23 or 3.55 is recommend; if the Tremec has an over drive gear, then you can (and should) go higher.

With limited highway driving, a 3.91 is also do-able.
Most tire combinations will out you around 3000 rpm at 60 with that (+/-).
(I'm still debating that for my car.)

Archer

rcknrolfender79

For better race performance I'd go with a 3.91 ratio (Dana if you can get your hands on it, but it will be tough to find and probably not cheap, assuming your wanting a rear end that will bolt right in) But 3.91 is a decent ratio that will give you plenty of pull and wont have your engine completely wrapped up at 60mph. If you don't mind doing fab work you could probably find a Dana in an old 4WD pickup or jeep(not sure how the wheel base would be though may have to have it cut down.. and it may not be long enough) Unless your gonna go pro street style and tub it then none of that really matters and you would save a lot more money going with a dana out of something else. Also Dana's would probably be easier to find parts for as they are so common among 4WD applications. But then again the 8 3/4 came in a ton of vehicles as well.

Just my 2 cents.

Dave E

Has any one used the "Strange Gear" brand axles? Really leaning towards the Dana myself and the trans is an overdrive trans so we are thinking 4 and up for gearing.

Gorts 5th

I have read some good advice . With that motor and the weight of the car it will burn, roast , and pretty much shred your tires with anything higher than 355 s and still with this set it will have no problem smokin em ..ive always set my combos for "squat and get" not " sit and spin " and any slippage is no good and can be down right dangerous ive seen and had many close calls with apponets loosing control , specialy short wheel base cars like stangs
now im wondering, with that engine your effective hp curve can be anywhere frm 2500-7500, trending the cam is more matched to mopar geomety not a chevy for instance a Racer brown cam "old school " or a voo doo cam but I digress your tranie gear ratios will play a great rol if when you shift you start as close to the bottom of your curve at close to your highest tork /power curve , insted of dropping at the near top of your curve.
mabe food for thought.

Archer

Dave -

3.91 or 4.10 tops.
You'll get the off the line torque and still cruse like a "regular car" on the highway.
I'm a little jealous...

Archer

Gorts 5th

He will ne turning at least 2800 rpm at 55mph

Archer

Gorts -

With the overdrive?

Archer

Gorts 5th

With od my set up 390 gear she turns 2000 rpm at55, at 80 with od and lu she turns 2200 rpm
the 2000 stall is diffent than low stall every wher I go cruzin she turn 2000-2200 in town ... dodge really did their home work on this its a great streetable stall anyway thats off point .

NeverEnoughAuto

"I like the 9" ford rear, got alot of gears selection choices.

moparted

that tranny will break before the 8 3/4 will

Gorts 5th

Yea that is one big stick of iron under there
but the trany with the proper mods Is very dependable