Hi everybody,
I've got (4) 9" drums, small bolt pattern, and 7 1/4 2.76 rear on my low mileage 72 Scamp. I'm looking at a 75 Duster (rusted out frame) with Disk brakes up front and large BP wheels as a parts car.

Question is: does this 75 likely have 10" rear drums? And does it likely have a 8 1/4 rear? I am trying to get the seller to validate those specifics before I drive down too look at it but figured this is common knowledge for you guys.

Also, is 75 a good year for a donor car? Would there be a better year? Anything else that needs to be considered for a successful swap?
Thanks,
WTS

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72 Scamp 225 /6, auto, radio delete, alum super six, cold air duct, pertronix ignitor II and flame thrower, 3.23 rear, 2.25" free flow exhaust

In general I'd say a '75 would be a good car for a big bolt pattern upgrade. Any 1973 or new A body with disc brakes should work though as I don't think there was much difference between them.

I can't ID the rearend positively for you but the seller should be able to describe what it looks like. That is, is it shaped like stop sign, does it have 10 bolts holding the cover on, etc. That will ID the rear for you.

As for the rear brakes, I'm in the camp that says they don't matter that much on a street car driven at normal traffic speeds. The fronts do 80% of the work. Either 9 inch or 10 inch will work just fine as long as they are properly adjusted and maintained. Put the big 11.75 rotors up front (if you have 15 inch rims) and you should be able to stop a truck.

Excellent, so I'm looking for a hex or octagon shape with 10 bolts. I'm not worried about strength of the smaller 7 1/4 unit, but I would like to put Sure Grip gears in so I have a chance of this car moving through the snow up here this winter!

Of course I'm hoping to get lucky on a 3.23 with SG, sway bars, etc..
Thanks for the info

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72 Scamp 225 /6, auto, radio delete, alum super six, cold air duct, pertronix ignitor II and flame thrower, 3.23 rear, 2.25" free flow exhaust

Sorry, my post wasn't perfectly clear. I was just suggesting some questions you could ask the seller to ID the rear end. The 8 1/4 has a round cover with 10 bolts. The 9 1/4 has a hexagon shaped cover with 12 bolts. Check out this link for more clarification. http://www.moparts.com/ub/ubb/Forum15/HTML/000004.html

Unless the car's been modified you'll be stuck with two axle options at this point:

hexagonal 9 bolt cover for regular duty 7 1/4" with 10" drums for disk brakes or,

round 10 bolt cover with large axle tubes with 10" drums for heavy duty use: 8 1/4" rear



so either way, you're in good shape for LBP all the way around...

I'd even go so far as to grab the better seatbelts for your car(if still intact), and anything else that looks good to 'save out', the only thing that doesn't trade is the sheetmetal, wiring harness, grille, tail-lights, and windows.

good luck on the swap,

-D.Idiot

p.s. you may need to use your driveline or have another one fabricated since the duster has the short wheel base and the Scamp/Dart has a longer one so the Scamp driveline will be a few inches longer than the Duster one.

Thanks for the clarification guys. I'm still waiting to hear back from the seller- I'll let you know how I make out.
WTS

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72 Scamp 225 /6, auto, radio delete, alum super six, cold air duct, pertronix ignitor II and flame thrower, 3.23 rear, 2.25" free flow exhaust

Here's a question that you shoulod be able to answer right away.....What did/does the '75 have for an original engine?

If it was a slant, it's probably a 7.25, but if it was originally a V8, then there's a strong possibility that it's an 8.25.

Roger

I wouldn't say strong. I have seen plenty of 318's with 7.25" behind them in junkyards.

From '73 on the 318 got a 7.25" standard, unless you added the 8.25" for heavy duty use.

Even then, my 74 Duster with 225 /6 and 3spd manual got an 8.25" with 3.21's....(non A/C car...has disc brakes...but lots of car with discs and 318's still got 7.25" rear with 10" drums)...


-D.Idiot

So no real method to the madness???

This car is a slant, but I'm hoping for a strange option package like Didiot's!

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72 Scamp 225 /6, auto, radio delete, alum super six, cold air duct, pertronix ignitor II and flame thrower, 3.23 rear, 2.25" free flow exhaust

Unless you do really stupid crap like spin the tires around corners or spin from gravel onto pavement, you really shouldn't have a whole lot of trouble with a 7.25 rear.

If you do do stuff like that, you will tear up anything.

My Duster was a Slant/disc car. It had a 7.25 with 10" drums.

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Official Cookie and Mater Tormentor.

Heck, you could even get 9" SBP drums all the way up to mid model year 1976....


jeez...

-D.Idiot

YEP! That's what my 1976 (mfg'd late 1975) came with!

Thats news to me! I thought A bodies went to big bolt pattern in 73?

Yes, they started LBP in 1973, but it wasn't mandatory...it only appeared depending upon your options like...disc brakes, 10" front drums, later some of the 9" got LBP, but I figure at that point the assembly worker just threw on whatever was on the pallet next to them ...


not much rhyme or reason to it really....

-D.Idiot