Thread: 1968 Plymouth Valiant 1st Gen HEMI

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I’ve been working on the EPAS electric power steering. I had purchased their A Body unit a few months ago and the instructions and You Tube video for modifying the steering column and installing the unit seemed pretty straight forward. Also informative were a couple of the threads on the forums from guys who have used EPAS in their cars.

From one of the threads on another site I found out that in addition to the A Body Kit, EPAS also sells a kit for “Dodge Demon/Duster”. The “Demon/Duster kit” is actually the one needed for the 67 up cars. As far as components go the only parts difference between the 2 kits appears to be the floor bearing retainer which is triangular shaped on the A Body kit (which also includes an aluminum floor plate that is not used on the 67 and up cars) and diamond shaped on the Demon/Duster kit (which makes it easier to attach to the existing floor plate). The instructions (from the EPAS site on the internet) for the measurements on where to cut the column and shaft are also different.

Z EPAS 1 by M Patterson, on Flickr

I had ordered my EPAS unit thru Summit, but rather than going thru their tech line when I had questions I looked up EPASs number and talked directly to their tech section. I can’t say enough good about EPASs tech support. I called them a couple of times when I was putting the system together. They were quick returning my calls, knowledgeable about questions I had and very helpful. When we determined I needed a different bearing retainer plate they sent it out immediately and I received it in 1 day.

One of the most helpful tips they gave me was that instead of using the supplied measurements for cutting the column that it might be better to reinstall the column and then set the EPAS unit up next to it to determine exactly where it would best index in my specific car and I’m glad I took their advice as my measurements for cutting the column and shaft ended up being slightly different than those recommended in in the instructions.

I was warned on one of the sites I would run into interference issues with the steering and exhaust using a First Gen Hemi in the 68 and he was right. When we went thru mockup on the parts car we were able to clear the steering box using 56 manifolds but the steering shaft to the manifold was really close……close enough that I was looking at possibly having to build a 2 piece steering shaft with U joints at the firewall to clear the manifold.

The EPAS A body and “Dodge Demon/Duster” kits are designed to run a single straight shaft from the power steering motor down to the steering box. If I had been doing a Small Block, Big Block, and probably even a second or third generation HEMI the installation would have been as straight forward as the instructions and videos depict.

I however am the idiot who’s bound and determined to use a first Gen Hemi. When we were test fitting the PS motor/column I noticed a couple of things. The floor plate that bolts to the firewall and supports the end of the original column (and is used to mount the EPAS floor bearing) has oversized holes punched into it. These were probably used to shift the plate as necessary for shaft alignment as the car went down the assembly line. By shifting the plate all the way to the left and even elongating the holes if necessary I can gain the clearance I need for the steering shaft to manifold clearance. Talking to the tech section at EPAS we determined I could use a U joint off the end of motor instead of the straight coupler (shown in the picture) and move where the shaft comes thru the fire wall for added clearance. The shaft coming thru the fire wall will be cut off just past the firewall, then a second shaft with U joints on each end will be used to connect the shaft from the motor to the steering box.

After a lot of measuring and test fitting I had the column modified and the PS motor attached.

Z SC by M Patterson, on Flickr

Will I wish I’d put a new turn signal switch when I assembled it…..probably…. but the old one worked so we’ll see how long it lasts.

We got the column and motor installed yesterday, along with its control box. It’s hard to get a good picture of it, but I’m really happy with how it fits in the car.

Z SCI by M Patterson, on Flickr

I’m waiting on the U-Joint for the end of the PS motor before I can finalize the shaft thru the firewall part of the project and I still need to get the wiring done including extending the wires on the rheostat so it will mount to the dash where I want it but the hardest part of the project is done.



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Slick looking unit. So was regular power steering not available for this car?

The Valiants were available with PS, but the steering box is physically larger than the manual boxes. Swapping in a Big Block (like the car had when I bought it) or a HEMI usually makes it impossible to use the PS box. The manual steering boxes with the 24:1 ratio really isn't too bad to drive even with a BB or HEMI so most guys live with that or even the quicker 16:1 "firm Feel" boxes. When you do a swap like that it normally puts the car in the not driven very often toy category anyway.

I had researched electric PS for the 57 Plymouth a few years ago and probably would have gone with that except having a 4 speed the clutch and brake pedals prevented having any room for the electric motor. In the case of Plymouth’s factory PS units, while bolt in, they are hard to find, expensive and usually needed rebuilt (anywhere between $300-$700 range to have then rebuilt). The biggest complaint I had about the factory PS was the horrible road feel they had which was why I originally built the car with manual steering.

On the Plymouth I went with a conversion hydraulic PS that used a later steering box. The kit included a rebuilt steering gear, adapter plate hoses etc, basically everything except the PS pump, brackets for the pump and pulleys (I’d done a HEMI swap so those weren’t available). The kit cost about $1100 and required steering column modifications.

The electric PS cost about $1300, but eliminates the need for a PS gear, pump, brackets and pulleys. In the end cost is actually a bit cheaper than a lot of non-factory PS conversions. Column modifications are necessary, but relatively speaking are simpler than a lot of the conversions.

Too be perfectly honest a big selling point for me was I’ve never done an electric PS conversion and wanted to see how easy/hard it is.

Sorry for the long winded reply, but after yesterday my back’s killing me and I have too much time to sit at the keyboard



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That makes sense. I agree some of the older power steering were so mushy feeling, but you could drive with one finger...

A quick update on the AC. I got the ducting run and although the heater hoses and AC lines have yet to be built/connected, I was able to test the unit and check for the volume of air that would come out of the vents. I’m very happy with the results. There’s good velocity coming out of the under-dash vents and the floor air diverters work well. I’m especially happy with the defrosters, they shouldn’t have any problems keeping the windshield clear (this was the major complaint I had with the last aftermarket unit I installed).

Most of the time spent on the car the last couple of weeks has been in the interior. I’ve been sorting out wiring for the accessories I’m adding (electric PS, AC, Radio, GPS, cruise control etc). We also redid the carpet in the rear seat area. I’ll post more on that when I have that part wrapped up.

Yesterday we were at a point where it was time to install the mock-up motor and transmission in the Green car. We’re doing a final mockup basically as a quick check to make sure that no new clearance issues popped up due to any differences in the bodies. I figured that there would be some additional clearancing required but to my surprise the engine and transmission actually seems to fit better in this body than it did in the other 68.


Z MU F by M Patterson, on Flickr

While the mockup engine and transmission is mounted I’ll go ahead and finalize the steering and probably some other little things prior to installing the real engine and transmission.

Cade wasn’t available a couple of Sundays this month so I pretty much concentrated on the interior and wiring which is now pretty much done.

So far I’m happy with the AC/Heat unit. I got the ducting run (making sure it didn’t interfere with the wiper linkage was kind of a PIA). Although the heater hoses and AC lines have yet to be built/connected, I was able to test the unit and check for the volume of air that would come out of the vents. I’m very happy with the results. There’s good velocity coming out of the under-dash vents and the floor air diverters work well. I’m especially happy with the defrosters, they shouldn’t have any problems keeping the windshield clear (this was the major complaint I had with the last aftermarket unit I installed).

Other than the under dash vents the other visual mod for the AC/Heat unit was redoing the factory heater control panel and using the controls provided with the unit.

Z interior 2 by M Patterson, on Flickr


When I bought the car at a glance the rear seat area didn’t look too bad, but the more time I spent on the inside of the car the less I liked it. On closer inspection it looked like it had been upholstered with whatever leftover black material they had on hand. It was mismatched compared to the front carpet and when we got the rear seat/trunk divider out we found it was just the deteriorated original cardboard piece with insulation glued on one side and carpet on the other.

I started by cutting a new divider from 1/8” masonite (if I was still using a fuel cell or planning on seriously racing it I would have built it from metal).

Z Divider by M Patterson, on Flickr

That was carpeted and insulated and a pair of speakers added (I would have mounted them in the package tray but the rollbar braces now go thru those holes. they’re so close together due to the trunk bracing). Then we put new carpet that matched the front carpet down and called it good.

Z interior 3 by M Patterson, on Flickr

Then it was on to the dash and figuring out where to place all the accessories I wanted and do the necessary wiring. I had to do the wiring for the new gauge cluster, AC, OD transmission, electric fuel pumps, stereo and speakers, satellite radio, GPS, cruise control ect ect.


By the time I had added the control knob for the power steering, cruise control, stereo, Satellite radio, GPS and controls for the floor air, it’s a little busy looking (although the GPS and Satellite radio will likely be removed except for long trips). I had looked at using a double DIN sized unit that would have still provide me the GPS, Satellite radio, FM radio, and a bunch of other features I’d never use (although a backup camera while not really necessary with this car, would have been a neat toy till the novelty wore off). I’m capable of doing the dash mods to do a nice installation (including relocating the heater/AC control panel) but it was more work than I really wanted to get in to and the satellite radio and GPS are set up to be transferable to 2 other vehicles I own, so I stayed with that.

I also added a couple of cup holders to the console (had the top of the console been in better shape I might fell a little bad about cutting those holes).

All in all I happy with the way it turned out especially the gauge cluster. The set up when I bought the car was pretty useless for a street car with the tach and aftermarket gauge cluster locations.


68 Cluster 1 by M Patterson, on Flickr


The new cluster is a lot easier to see and monitor what’s going on.

Z interior 1 by M Patterson, on Flickr


Yeah I know the metal flake steering wheel might not be to everyone’s taste (I actually thought about adding a Tuff Wheel instead). I was working in a Chrysler Plymouth dealership when these cars were new. At that time K Mart was the first big box store and everyone one of them had an automotive section with a selection of the metal flake wheels in various colors. At least where I was they were a popular add on. It just takes me back to a happy time. On the plus side the horn actually works now LOL


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You've been busy, and it looks GREAT!! I think the biggest improvement on defroster performance is triggering the AC Compressor to dehumidify the air. In the old days we had to wait for the engine to warm up and provide enough heat to warm the defroster air, and then have enough flow to warm the inside of the windshield. Having the AC on evaporates the fog soooo much faster!
I really like your dash layout! The old column mounted tacos really blocked the view!