Modern Drivetrain Swap into '65 Valiant

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ScamperTom

ScamperTom

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In the spring I acquired a '65 Valiant wagon. The exterior shell seems to be in fine shape, but the floor is completely shot. The motor is locked up and I wouldn't trust the transmission either at this point. Since I'll have to complete major metal repairs as well as a complete driveline swap in any case, I would like to go with a good modern overdrive transmission.

The transmission is the focus here, as driveability is my priority with this car. I would like to keep a small motor in the car - no v8, although a 273 would be cool. It would be nice to keep the slant 6, but it doesn't seem like there are any straightforward overdrive options other than a 4-spd. Budget and simplicity are key. I was thinking about putting in a jeep 2.5 i4 or 4.0 i6 with an ax-5 out of a mid 90's Cherokee. Plenty of power for a small motor, and lots of support for the jeep guys. It would be nice to have a T-5, too. I could grab the engine and trans out of an S-10. Of course, maybe the work required to move away from the 904 isn't worth getting rid of the slant 6.

What do y'all think? What good motor/trans combo would be a good replacement for the factory setup?
 
Just my option but a Jeep 6 stands too tall to fit under the hood. A good running 318 with overdrive trans would be good, inexpensive and reliable.
 
keep in mind you’ll likely need to do transmission hump mods with just about any OD, other than the 833 OD
 
I'll second the 3.9 or Pentastar. At one time I also had the wild idea of a complete 3.5 LH platform drivetrain and suspension in an A-body. I grew to dislike the 3.5 enough that it's an idea that I have long ago abandoned...
 
The trans tunnel is tiny compared to any OD trans 'cept maybe a Ford AOD. You can cut the tunnel but youll have to section it to retain the torsion bar mounts.
 
Wilcap will make you an adapter for the GM 2004r transmission. They have the program as there was a group buy a while back. They may have some left over.
 
RustyRatRod said:
Wilcap will make you an adapter for the GM 2004r transmission. They have the program as there was a group buy a while back. They may have some left over.
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I did some reading on the 200r4 trans. Having rebuilt at dealer level a bunch. They are a good trans and smaller than the 2wd Mopar OD so fit ment is better in an Abody. Sadly Mopar newer engine swaps are a PITA unlike Chev or Ford swaps. I wish Ma MoPar was as kind to the aftermarket kingdom as the above mentioned brands are. Just the fact aftermarket parts like door handles or mirrors for a 50 year old car have to be licensed in order to sell let’s you see the strangle hold they have on the market. I read both of the posts mentioned above (3.9 od and the 3.6 pentstar) both ALOT of work and cost. IMHO- time is not cheap. A 3.9 and OD trans is easiest and best bang for the buck for transportation. Parts readily available and it still looks very different at car shows to catch people’s eyes. That is is you still want a “something different”
Again MHO.
 
Syleng1 said:
Just my option but a Jeep 6 stands too tall to fit under the hood.
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I didn't even think about the jeep motors being too tall. That's something I'll definitely have to check. I guess that's the whole reason for the slant in the first place.

65 Dartman said:
keep in mind you’ll likely need to do transmission hump mods with just about any OD, other than the 833 OD
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Since I'll have to replace the floorpan entirely anyway, modifying the crossmember and trans tunnel doesn't seem like that much extra work. An 833 OD with with slant six is definitely the simplest, but they seem hard to find and expensive.

RustyRatRod said:
Wilcap will make you an adapter for the GM 2004r transmission. They have the program as there was a group buy a while back. They may have some left over.
Click to expand...

Do you mean for the /6? That would definitely be something to look into, as I've heard nothing but good things about the 2004r.

The big problem is that I want to stay away from both v8s and adapters, which seems to limit options. The pentastar and T5 swap on the forum looks really awesome and well done, but involves too much fabricating for me. I'd rather have the trans and motor work with just factory parts: no custom machined pilot bushings, etc. So basically I guess I have to choose the best transmission and then pick an engine that would work easily with it. (The only exception I would make would be if I could easily stay with the slant 6.) I thought about a 3.9, but it seems like after figuring out all the ignition and carburetion problems involved in that swap I'd be left with a motor that's slightly worse than a 318 and not much lighter. I love the 318 I just don't really want an engine that is such a tight squeeze on this car. I even considered a volvo motor, since 1990's wagons can be had for a nickel these days.
 
ScamperTom said:
I didn't even think about the jeep motors being too tall. That's something I'll definitely have to check. I guess that's the whole reason for the slant in the first place.



Since I'll have to replace the floorpan entirely anyway, modifying the crossmember and trans tunnel doesn't seem like that much extra work. An 833 OD with with slant six is definitely the simplest, but they seem hard to find and expensive.



Do you mean for the /6? That would definitely be something to look into, as I've heard nothing but good things about the 2004r.

The big problem is that I want to stay away from both v8s and adapters, which seems to limit options. The pentastar and T5 swap on the forum looks really awesome and well done, but involves too much fabricating for me. I'd rather have the trans and motor work with just factory parts: no custom machined pilot bushings, etc. So basically I guess I have to choose the best transmission and then pick an engine that would work easily with it. (The only exception I would make would be if I could easily stay with the slant 6.) I thought about a 3.9, but it seems like after figuring out all the ignition and carburetion problems involved in that swap I'd be left with a motor that's slightly worse than a 318 and not much lighter. I love the 318 I just don't really want an engine that is such a tight squeeze on this car. I even considered a volvo motor, since 1990's wagons can be had for a nickel these days.
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So what's the problem with adapters?
 
RustyRatRod said:
So what's the problem with adapters?
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Because it seems like an expensive way to go with a complicated setup. You need an adapter, plus a custom flexplate or whatever else. Only worth it, imo, if I get to keep a slant. I get why people use adapters - they like their motors - but if I'm swapping powerplants it doesn't make sense not to keep the engine and trans at least in the same company. It would just be simpler.
 
RustyRatRod said:
So what's the problem with adapters?
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Agree! Even Chrysler used adapters! Some of the early Hemis used them as did Chrysler in 64-67 on the A100 vans with the slant to 727/904 adapter. With this adapter, you could keep the slant and add the A500 OD.

B46D104E-33BF-4E74-972D-291368A3D4D3.jpeg
 
Syleng1 said:
Just my option but a Jeep 6 stands too tall to fit under the hood. A good running 318 with overdrive trans would be good, inexpensive and reliable.
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That's why Ma Mopar slanted the 6!
 
ScamperTom said:
Because it seems like an expensive way to go with a complicated setup. You need an adapter, plus a custom flexplate or whatever else. Only worth it, imo, if I get to keep a slant. I get why people use adapters - they like their motors - but if I'm swapping powerplants it doesn't make sense not to keep the engine and trans at least in the same company. It would just be simpler.
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I have a Mopar A833 four speed bolted to a 1956 model Chrysler 331 Hemi. Bolted right on. A deaf, dumb, mute, blind, retarded chimp could have done it. You're talking about a 1" plate and a 1" spacer for the flywheel or flex plate. Nothing complicated or complex. Right. From your original post, from what I gathered, you were keeping the slant six. Have you decided against that now?
 
Why couldn't a guy fab a custom pan and pickup, and "slant" a Jeep 6?
 
ScamperTom said:
That does seem to be a good way to go except that they’re about as common as hens teeth.
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they are not impossible to find. I traded some 340 torsion bars for the one I have (pictured). I have an 87 D100 that originally came with a slant/904 that I will most likely use the adapter with a built slant and A500 in the truck
 
RustyRatRod said:
I have a Mopar A833 four speed bolted to a 1956 model Chrysler 331 Hemi. Bolted right on. A deaf, dumb, mute, blind, retarded chimp could have done it. You're talking about a 1" plate and a 1" spacer for the flywheel or flex plate. Nothing complicated or complex. Right. From your original post, from what I gathered, you were keeping the slant six. Have you decided against that now?
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65 Dartman said:
they are not impossible to find. I traded some 340 torsion bars for the one I have (pictured). I have an 87 D100 that originally came with a slant/904 that I will most likely use the adapter with a built slant and A500 in the truck
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OK well now you're making me think that this adapter idea could actually work. From some searches on other forums I was getting the idea that working with the slant was just going to be way too difficult. I'd like to keep the slant but I don't want to do a ton of fabrication (as seems necessary with the T5) to get a different trans to work with it.

The priority is the transmission. If I'm using a trans from the 90's, say, it seems to make most sense to also use an engine that already works with it, unless the slant will fit fairly easily and cheaply, as you say. I'm just not familiar enough with different vehicles to know what would be a good package to use in place of the slant.

67Dart273 said:
Why couldn't a guy fab a custom pan and pickup, and "slant" a Jeep 6?
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Now that would be a challenge way beyond my skills, but cool to see! I foresee some difficulty mating a transmission to that. Slanting a transmission would probably affect lube flow, right?
 
RRR I have a Wilcap adapter on my 418 stroker in my Demon. I used a built 200R so I would not have to do much cutting. You are right there is nothing wrong using an adapter.
 
A 2004r onto the slant six would probably be the ideal mixture of driveability and originality but I do like that ax-15 idea.
 
Best to copy since pioneering a path is complicated engineering with many dead-ends. The slant-six just barely fit. They offset the water pump housing and cast it into the block, but even then no room for a clutch-fan in your 1965, and slanting the engine allowed a lower hood. A small-block gives more room to the radiator and isn't too tight on the sides. On the plus side, your K-member is the same for a small-block so just need the motor brackets. You also need a V-8 steering cross-link to clear the oil pan, though some 1966 slant ones have the same ~1" drop (slant is ~0.5" drop). You need a 1964-65 oil pan on the small-block w/ a "dent" to not bump the steering linkage. That will fit any 273, 318, 340, or 5.2L Magnum, but not a 360 or 5.9L (larger rear hump). Some people dent a later oil pan to work. I hope to fit a V-8 Magnum intake on my 1965 273 someday, and looks like the air plenum will just barely clear the hood. Some have fit Magnum engines and transmissions, so "should fit", but you must reform the transmission hump to clear their 4-spd transmissions.

I suspect that hood height will limit you to a pushrod engine. Some have fit a GM LS V-8 and transmission, which are common and cheap, with many aftermarket parts. But, insure an early A since the engine bays are ~2" narrower. If you want to pioneer, the Chrysler 3.8L V-6 is pushrod and was used a few years in Jeeps so there is a RWD version (different mounting bosses) and a RWD transmission, hopefully in a 2WD version (no transfer case). But, it has a 60 deg bank angle, instead of the 90 deg of the 3.9L Magnum, which is better balanced for a V-6 but also a bit taller. Most 4 cyl engines that come to mind are overhead camshaft, so likely too tall. When I took the head off my 2.4L DOHC Plymouth engine, I was amazed how far down the top of the block sat in the engine bay. I think most modern engines are fairly easy to wire since the whole harness and controller can be used, with just a few wires to connect to the car, assuming you don't go so new as to have an electronic throttle.

If your main goal is a better transmission, there was a late 1980's version of the 904, termed 999 (I recall), but google. It at least had a lock-up torque converter, if not an overdrive. I saw one (I think) in the junkyard on a ~1980's van w/ slant-six, painted grey so likely US Navy (seems they preferred Chrysler's). The transmission looked almost new, so was tempted to pick it. Note, that the crankshaft hole in a 1965 engine is (usually) too small for the torque converter snout of a later transmission (1967+ recall). One fix is to swap the whole front guts (input shaft) of the transmission to use an older torque converter (lose lockup feature) or buy a custom torque converter. If going the other way, you can buy a thin ring to fit them tight.
 
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There’s a jeep around the corner from my house. I guess I’ll just have to go measure to see if the motor will fit. One of the big things turning me off from a new swap is the wiring. I imagine new engines are more difficult than old ones, but I suppose if you cut and pasted the entire harness it might actually be easier than dealing with the rather haphazard mopar system.

Youre right the trans is the priority. But simply having a lockup converter won’t be enough of an upgrade to satisfy me. It would also be preferable to have a package that works with minimal tinkering, so if i did go with a 999 I’d probably just try to use the engine it came behind.
 
Just an FYI.....a 273-318-340 oil pan will not fit a 5.2 Magnum. All Magnum motors, whether they are 5.2 or 5.9 use the same rear main cap...which is the same size as LA 360 motors.
 
JDMopar said:
... All Magnum motors, whether they are 5.2 or 5.9 use the same rear main cap...which is the same size as LA 360 motors.
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Good info. Never been there, but thought I read that the 5.2L had a smaller hump and same as the 271-340. Indeed, I recall reading it used the same oil pan as the 5.9L, but the gasket is extra-thick there to fill the gap. If anyone has been there, chime in.
 
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