trans / torque converter swap ...help plz

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bighammer

bighammer

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:prayer:please help me figure this out...

I'm swapping in a 360 from a donor truck. I can also swap the tranny if I want. (Obviously they were meant to work together). I don't know if the truck tranny will be a direct bolt in, or if it has any advantages over the original tranny that came with the car, so should I keep my trans or swap it along with the 360?

If the consensus is to keep my original tranny, would I need to use the torque converter from the 360 truck or keep the original torque converter?

If I put in the truck tranny, is it a 'bolt in' swap with the same drive line?

The truck is a 1991, BTW, and the car is a 70 Dart v-8 auto car. Both trannies work well as they are in both vehicles, they shift strong, no slippage.

Also, the truck already has the flex plate needed for the 360, but the car takes a different torque converter, right?

Both trannies will bolt up to a small block, and they both have their own specific torque converter... right? or not?

I just re-read my post, seems too confusing and I'm sorry for that. Hopefully it will make some sense to somebody :banghead:
 
I'm guessing your Dart has a 904 trans. right? I'm also guessing the truck has a 727 or 518 overdrive trans. as I've yet to see a 904 behind a 360 in a truck. Plus I don't think the 904 was even around in 91, I think it was all A500 overdrive by then.

With that said I doubt you'll be able to use the truck trans. easily as most likely it's a overdrive trans. which won't fit in the trans. tunnel of an A-body without some reconstructive surgery. If by chance it is a 727 it will fit in the A-body but will require a different driveshaft and possibly different mount.

If I recall you now have a 318. To use the 360 you need either a 360 torque converter (again due to the truck trans. most likely being a 727 or A518 it's torque converter won't fit your trans.) or a B&M or TCI 360 to 904 balance plate that they no longer make. It's possible the B&M/TCI plate made for a 727 may work, I haven't tried it but have read once that a fellow said it worked.

IMO your best bet is to leave the 904 in your car since you say it works good. You don't need a 727 until you get way up there in power and by using the smaller lighter 904 you'll get better performance out of the car. The only issue is correcting the balance issue. Here's 2 links to a place that sells remanufactured converters cheap. The 1st link is for the high stall version that'll give you a little more performance and the 2nd link is for the standard low stall unit. Both are pretty cheap solutions to bolting the 360 to your 904

http://www.bulkpart.com/2/product/A904tcN/398.html

http://www.bulkpart.com/2/product/A904tcN/388.html

Or if you have about $250-300 to spend on a converter call Hughes Performance and have them make you a real good unit with even higher stall yet. A 2500-2800 stall will still drive super good on the street and give you a lot more take off. I've read they don't charge any extra to weld the weight on needed to properly balance a 360 and their a real good converter and competitively priced. Here's their website

http://www.hughesperformance.com/
 
My 91 Dodge has a 518 O/D trans in it. You would have to rework the trans tunnel to put that in your Dart and rig a switch or by the kit to make the O/D work.
 
Excellent info Fishy, just what I was needing. The 904 will stay in the car. I wasn't considering a torque converter, but it looks like I will be needing one... I clicked on the ones you showed, the ones from bulkpart.com, the price is pretty affordable, prolly (obviously) not as good as the ones from Hugh's, but any experience with them? I would likely go with the higher stall one, but they don't say what stall speed (?)

My car is planned as a weekend cruiser with a little 'muscle'

THANKS! This helps!
 
The high stall one is a re-issue of the factory high stall unit. The torque output of the engine affects how much it'll really stall but I'd wager a guess that it'd stall right around 2000 behind a stock 91 360. I haven't used any converters from Bulkpart but I have bought a lot of transmission rebuilding supplies from them. Very good company to deal with. Even though I haven't used any of their converters I wouldn't hesitate to if I needed a stock unit.
 
gremlin said:
You could always weld the neccessary weight on. http://www.ebay.com/itm/Torqueflite...Parts_Accessories&hash=item337196bc4d&vxp=mtr

That's a good idea if he has the welder, or can get it welded cheap enough.
Click to expand...
Fishy68 I wonder if you can confirm this. I had a guy at a trans shop cut and clean my converter and he says every time you cut one open and weld it back, you gain approx 500 rpm. You ever heard that?
Click to expand...

I'm a long shot from a converter specialist but I don't see how that's possible. The angle of the fins is mostly what determines the stall speed. If he's not changing them it should remain the same.
 
Just put a 360 into my 70 dart you can
Keep your converter and 904 but you
Will need to get a b& m flexplate for
The 360 it makes up for the external
Balance issue because it is like a pie
With a piece cut out it's about $100 shipped
 
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