automatic overdrive

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Since you're going to have to cut the floor, regardless......any of um. People have used the GM OD transmissions, with an adapter of course and the A500 and A 518 Chrysler transmissions. I'm sure there have been more.
 
There's more threads about this than I can count...
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If it's a 66 or older, go with the A500. The 67 newer Darts were available with the 727, so the front of the floor clears A518 fine, Both need clearanced at the back.
 
727 out of a 89 dodge pickup truck, electric overdrive.

no floor cutting.
 
1..So far as I know, it's 904 based AKA 42RH series
2..GM 200R4 or 2004R whatever they are---genuine 4 speed, not OD, but hard to find and a bit weak
3...Gear vendors aftermarket, "not sure" if you have to cut the floor

The Mopar OD you must extensively rework the rear cross member.

And yeh. There ARE a lot of threads on this, and a couple with great photos showing the process and crossmember mods
 
Curious, how is it not an OD? Final gear is .67 and that is the very definition of an OD.
Picky selection "in terms". What I meant is that it does not have "an over drive" (unit). It has an overdriven gear but it's not a separate overdrive unit. "It's not an over drive"

It's a built in gear not a separate OD unit. The Mopars have a separate OD component built into the big fat modified tail housing.. ...a completely stand alone physical unit. The mopar overDRIVEN 4 speed is also technically not an "over drive unit" because they took the 3rd gear slot and re-geared it to an overdriven gear. This is opposed to an "over drive transmission" like the older 3 speeds which had "stock" 3 speed guts with a separate OD unit in a modified tail housing
 
Picky selection "in terms". What I meant is that it does not have "an over drive" (unit). It has an overdriven gear but it's not a separate overdrive unit. "It's not an over drive"

It's a built in gear not a separate OD unit. The Mopars have a separate OD component built into the big fat modified tail housing.. ...a completely stand alone physical unit. The mopar overDRIVEN 4 speed is also technically not an "over drive unit" because they took the 3rd gear slot and re-geared it to an overdriven gear. This is opposed to an "over drive transmission" like the older 3 speeds which had "stock" 3 speed guts with a separate OD unit in a modified tail housing
Yep splitting hairs there. Anything less than a 1:1 ratio is considered a O/D. (over driven) It really doesn't matter if the transmission has a old school design O/D unit bolted to the back or a modified tailshaft design, anything past the 1:1 is a overdrive. Simple semantics.
 
An overdrive is a ratio that can be ADDED to any of the lower gears. That's how Ford came up with the first five speed overdrive trans. All they did was reprogram the computer to add OD to a lower gear; I think it was first gear, rather than just adding OD to third gear. Get an early A500 or A518 with a two or three prong plug.
 
what trans can be used for overdrive automatic behind small block in dart ?

My daily driver, completely self built.
1995 A500 (42RH) completely automatic with a manual shut off for either OD or converter lockup.
Stage 2 Transgo shift kit.
Tunnel hump modified (not floor cut) trans cross member redesigned, shortened driveshaft, longer speedo cable, some adjustable pressure switches and a couple of solenoids.
355 geared sure grip does 80mph at 2,300 and 25mpg on the hiway with a mild (350hp) 5.9 Magnum.

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Curious, how is it not an OD? Final gear is .67 and that is the very definition of an OD.

The Stage 2, GM 2004R with from Extreme Automatics with a bolt on Reid Bellhousing is the best transmission I've ever driven. If you run a lock-up converter, it's the closest thing to an automatic 5 speed going. I run a Precision of New Hampton 3800 rpm stall, lock-up converter in mine with 4.30 rear end gears, slapper bars, 2 passenger side SS springs and Nitto Drag radials. The only cars that pull on me out of the hole, so far anyway, are the AWD Nissan GTR's. Those things scoot.

I did have to cut and modify the torsion bar cross member, but the floor remained untouched. They are limited to about 700 hp once properly built though, so I'm going to have to switch over to a 4L80 for my upcoming build.

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The Stage 2, GM 2004R with from Extreme Automatics with a bolt on Reid Bellhousing is the best transmission I've ever driven. If you run a lock-up converter, it's the closest thing to an automatic 5 speed going. I run a Precision of New Hampton 3800 rpm stall, lock-up converter in mine with 4.30 rear end gears, slapper bars, 2 passenger side SS springs and Nitto Drag radials. The only cars that pull on me out of the hole, so far anyway, are the AWD Nissan GTR's. Those things scoot.

I did have to cut and modify the torsion bar cross member, but the floor remained untouched. They are limited to about 700 hp once properly built though, so I'm going to have to switch over to a 4L80 for my upcoming build.

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Nice! Precision of New Hampton are good converters. Not too far away from me.
 
No but a 200 4R is
...And when built is stronger than any 700 could ever be.

I did have to cut and modify the torsion bar cross member, but the floor remained untouched. They are limited to about 700 hp once properly built though, so I'm going to have to switch over to a 4L80 for my upcoming build.
Why not go with the Extreme automatics Stage III 200-4R? It's supposedly good for 1000hp/750ft-lbs torque. I know it isn't cheap but it's an easier swap than the 4L80 from what I understand.
 
Trucks and vans are the only vehicles that are worth putting an overdrive into. This cutting with the floor; okay, "crossmember" is not worth all the mess. If you want gas mileage then buy a second car; cheaper in the long run.
 
@lkopaska put a lock up 904 with a low ratio 1st gear in his Barracuda. It works great and get's good mileage with his 273-4.
 
2004s and 700s are JUNK. Lay out the guts from a 2004, 700 and 518 if you want a quickie course on strength. No contest; the GMs are stamped sheet metal whereas the Dodge is hardened machined steel.
 
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