225 to 360 swap... info needed

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DemonDave

DemonDave

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Looking at a 360/727 combo for sale locally that might be a nice upgrade from the 225/904 that my Demon is currently saddled with.

If I do the swap, I'd be re-using the /6 k-frame and utilizing the conversion mounts that Schumacher sells for ease of installation. I was wondering what to do for a tranny mount/crossmember. Will the stock crossmember work for a 727? How about the isolator? Any info would be appreciated since I've never swapped out a six before... I've been lucky that all of my past Mo's have been V8 cars! Can't afford those anymore... ;)
 
I wanna' hear this myself.........

There are a LOT of really sweet Slant 6 Dusters and Demons out there.......swap kits, crossmembers, and even driveshaft issues..... I need more INput, as "Johnny 5" would say..................

I had a chance to pick up a nearly mint 70 Duster with a six/904, mint interior, and already painted and striped to perfection, for under 7 grand...........If I had the swap problems all sorted out in my cranium, I might have jumped.......

If someone has all the bugs worked out, let's hear about it! :wav:
 
The only real issue with the swaps mentioned is the motor mounts and matching K members. The tranny crossmembers and mounts were all the same and in the same location. Since Schumacher has the motor mount/K member issue pretty well covered, all you really need is the bucks to pay for their kits. There really isn't much to know about the driveshaft changes. If the car is equipped with a 3 speed manual or a 904 auto the front yoke is the same, and 4 speeds and 727's used the same yoke. As long as you keep the same rear end, you can use the same driveshaft with a front yoke change if necessary. If you change rears, shorten the driveshaft accordingly, and this wouldn't be necessary if the rears had the same axle center line to pinion yoke length. This measurement is shortest on the 7 1/4" and the longest measurement is on the 8 3/4"/Dana 60 rears. They are only 2 3/4" longer than a 7 1/4" rear end.
Please note that I only covered what it takes to actually bolt in your engine/transmission of choice. Upgrading brakes, torsion bars, and exhaust varies from car to car (I had a new '74 318 Charger with big block torsion bars) so do some research before you start wrenching. Thanks to Schumacher and Chrysler engineering, the powertrain of your choice is a slam dunk. Hope this helps.
 
I can't say for sure in you application, but in early a-bodies you need the v-8 centerlink to clear the oilpan.

I also know that there are some issues in some models with fitting the 727 around the fire wall. I am only speaking from early a research, so you might be OK.

Radiator - I don't think a slant rad would be able to keep up with a v8 for cooling.

Should be dropping my 360-904 combo in in the next couple of weeks, I will update all with a thread when I do. (Still waiting on my headers from Harold!)

Oh yah, be sure to have a center sump oilpan, and appropriate exhaust manifolds/headers
 
A 727 is longer than a 904 so you will need to shorten the drive shaft about three inches (plus he amount needed if the rear is swapped). Cross members are the same and the tranny mount on the 904 will swap over to the 727. As others mentioned you will need to swap the front yoke on the drive shaft too.

When i did the \6 to 360 swap I did all the suspension / brake upgrades necessary to make the car safe after the swap.

I swapped in .890 torsion bars, did a disk brake swap and swapped in an 8.25" rear end. All of this was done while the \6 was still in the car and was driven this way for over a year while I tracked down a 360 to build. Since I had 6 into 2 headers on the \6 i had had a dual exhaust made up that was easily hooked up to the 360 headers when I did the swap. I had also picked up a heavy duty V8 radiator while the car was still a \6. The wiring was no issue, none needed to be lengthened and I just wrapped up the long ones with tie wraps.

You really need to get rid of the 9" brakes (if your car has them) before even considering the swap. They are woefully in adequate with the \6 and with the added acceleration of the 360 they become down right dangerous.
 
Thanks for all the excellent info!

I have an 8 3/4" that I'll be putting in the car when the engine/tranny swap happens... I'm also currently working on gathering up a 73-up disk brake set-up and all of the other required bits and pieces to make the car safe and fun to drive. There's a place in town that shortens/rebalances driveshafts so I have that covered when the time comes as well.

moparfreak77: Yes, the pic in my sig is my slant-six Demon punishing its rear tires! :D
 
CRAP....If you are spinning the tires off with the six, i would not change the motor..:toothy7: Rick
 
Ricksdust said:
CRAP....If you are spinning the tires off with the six, i would not change the motor..:toothy7: Rick
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:D

I'm actually surprised by the power of the six in the car! When I compare it to the 225 that was in my first Dart (1973 4 door 3-on-the-tree manual) it blows it away! I'm still ripping it out though. ;)

As an update to this thread, I've since picked a dropped centerlink off of a V8 Duster and bought the Schumacher mounts. Other parts collected have been an externally balanced B&M flexplate (so I can run a neutral balance convertor), a Thermoquad off of a friend's 1972 Roadrunner (400 car) and a 90 degree oil filter adapter off of a fellow forum member.

Haven't decided on headers yet, not sure what the best compromise between price and quality/ease of installation would be. Any insights?
 
DemonDave said:
:D

As an update to this thread, I've since picked a dropped centerlink off of a V8 Duster ...........
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Hope your didn't pay much for the center link. From 67 on the center link is the same regardless of whether it's a \6 or a v8. :(
 
dgc333 said:
Hope your didn't pay much for the center link. From 67 on the center link is the same regardless of whether it's a \6 or a v8. :(
Click to expand...

Hmm, good thing I didn't! Only $36 for the centerlink, tie rods and pitman arm complete. Oh well, you can never have too many spare parts!
 
For all the '72-down /6 guys out there going to small block. Trans dapt has a mount for like $60. I posted the part # before. Schumacher is great also, but these from trans dapt are sooooo cheap.
 
The devil is in the details. Radiater, hrottle linkage, kickdown linkage, speedo gear,etc.. I've done the \6 to V8 three times and cant remember everything thing to mention here.
 
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