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1970 Duster
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Posted by: ross2313

Hi, I am new to the board, I am thinking about buying a 1970 duster the problem is that it’s only a v6, I was wondering if anyone could let me know just how hard it is to swap in a v8, or if there are any sites with useful information. I am an amateur mechanic and I have never worked on a mopar car before. Thanks for all your help

Ross

Posted by: MikeT

i'm sure matt, ken or the OLE MAN can help you out on this one.

Posted by: MadScientistMatt

Well, if there really is a V6 under the hood, you are dealing with a truly peculiar engine swap. Dusters came with the slant six (the cylinders are all in a row slanted to one side, rather than arranged in three vees of two each) or a variety of V8's. Us slant six guys are rather picky about that distinction.

The swap is a bit involved. At a bare minimum you will need aftermarket motor mounts and either a bellhousing adapter or an automatic transmission specific to your engine. Chrysler designed three separate types of automatics - one for the slant six, one for the small block V8, and one for the big block V8 - then gave each a different bellhousing bolt pattern so that a too-weak transmission could not be attached to a too-powerful engine.

I highly recommend using a stronger rear axle with a V8; the Duster probably has a 7 1/4" rear axle which is not too durable if you put too much torque through it (Again, Chryslers match the rest of the drivetrain to the engine). If you want it to turn corners, I highly recommend stiffer front torsion bars. If it has drum brakes, I would recommend considering a disc brake swap. Some slant six guys use these other swapped parts list as an arguement for building up a slant six instead of a V8 swap - I disagree, as I say a serious slant six performance car definitely benefits from these upgrades too.

So, whether you want to start with this car depends on where you want to end up. If you just want a smallblock car, smallblock Dusters are relatively easy to find and will save you a good deal of effort. If you want something with a 440 Wedge, larger than stock discs (there are several options, from aftermarket to junkyard), and a heavily modified 8 3/4" or Dana 60 axle, you're not going to find that from the factory anyway. So your only options would be to start with a car like that, or someone else's project.

And if you're determined enough, you can try building up the slant six. I've heard of some street driven, naturally aspirated slant sixes running in the 14's, with the fastest slant six doorslammers in the 10's.

Posted by: ross2313

thanks for the help, it seems like quite the project i would be getting myself into.I think im going to go check out the car one more time and then ill probably be back with more questions, i love classic muscle so even though it seems close to suicide for a novice like me to attempt ill probably buy it anyways. Any sites or tips for how to take on this extenisve project would be greatly appreciated, i would hate to reinvent the wheel hundreds or times through out.

again thanks for the reply, any other advice or comments would be greatly appreciated.

Posted by: MadScientistMatt

One other piece of advice: Don't buy a rusty Duster! Check it with a refrigerator magnet (the flexible kind, which won't scratch paint) for signs of Bondo or rust, especially around the quarter panels. If you think the V8 swap is intimidating, correct rust repair is downright scary. It's cheaper in the long run to buy a car in good shape than to try and fix a beater.

Posted by: WymanV

Hi all-

New to this board-found it with a Google search. I don't race, but I still drive really frickin' fast

I've done this swap. The last time I did it, I swapped the K-frame out with one from a V-8 A Body car (a 68 Barracuda notchback, IIRC). If the body's solid and you have a good driveline, it's not a difficult thing to do. You'll probably be replacing lower ball joints as well, but since those old Mopars have spongy front ends it'll be wise anyway.

Like Matt said, be sure it's solid and worthy tho. I pay particular attention to the torsion bar mounts, but then again I kinda have to-I live in Wisconsin!

Ken F. (a different Ken...)

Posted by: EvilLS1

Welcome Ross & Ken!

Posted by: ross2313

Well the duster fell through before this last storm hit I finally got to look at it, and the car was in horrible shape. By the time i got it road legal again I wouldn’t have any money to make it a true muscle car.

My question is, just how hard is it to fix serious rust on these old cars. I have never worked on an old car before, just extensive reading. I ask because there is a 69 camaro for sale somewhat near me, which runs fine it just has some rust spots, it was a daily driven car with a nice v8 all ready in it. for 3xxx it looks attractive. any input would be appreciated. I can switch this to the gm section, but I figured seeing how it was about classic cars with rust I shouldn’t start a new thread.

Thanks

Ross

Posted by: Tang

I'm thinking $3000 for a '69 F-Body in good shape sounds like a helluva deal.

Posted by: 1970 402 duster

Hi I happen to have a 70 duster. forget about rust u can fix that,(except the frame rails) thats bad news. any way sure it's easy to swap a slant 6 for a 318 340 ,383 and 440 are alot more trickey(power stering,headers) all u need to worry about is engine mounts and wiring. if u get a 727 or a 904 with the car (preferably 727) keep that but u might want to re build it, (higher stall convertor,better valve body) And yes it will fit a v8. then try to find a 8 3/4 rear end with a 489 case + sure grip. then get u a pre 70 motor, (Made with better metal). stroke it, throw a .509 lift .292 duration purple shaft in the hole,and top it of with some 360 j or x heads,(port/polish/better springs), with a nice single plain intake with about 750 cfm,s on top. To light this mopar, use a mallory Pro comp magnetic distributor and a good mallory coil and ignition box. MOST IMPORTANT; GET U A BOOK ON A BODY'S. AND A 1970 VALIENT DUSTER SERVICE BOOK Trust me i have done it before

Posted by: 1970 402 duster

Like I said rust is not too hard to deal with. U can get replacement Q-panels rocker panels floor pans even frame rails, but that is still bad news. all u need is a mig welder a hammer and dolly, some good pliers and a trusty 4.5 inch angle grinder. I just got done with all 4 of my floor pans! The most important thing about getting rid of rust is to hit it hard, use good primer and don't trust the label on the cas that sais "stops rust" because that is utter BS. use a drill powerd wire brush to get rid of surface rust. And like i said get u a book on BODY WORK AND WELDING. Hope this helps

mopar or nocar

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