Customs 1949 Plymouth P17 fastback V6 swap.

I might be about to embark on a GM V6 and auto trans swap in a 49 Plymouth for a customer. Any tips or pitfall I might run into. Going to install a modern wiring harness. Anything I need to know about the 12V conversion. I don't even know if this car was 6V originally (not here yet) Just trying to do some homework in advance.
Any and all help always appreciated! JR.

 

That was fast! I agree with the premise of Mopar in Mopar, or Ford in Ford etc. But as I said it's for a customer. So in THIS CASE I'll let him be right.. He did say it is already converted to 12V and has an Alt. Also has an S-10 rear with 3:55 gears. I will be doing an e-brake to that. Will I have to change gauges, or switches? I'm thinking with a relay the headlight sw. will be ok. Just not sure about fuel and Amps.

 

Just do it as you would a Ford or any + ground 6v. Fortunately the little Plymouth does not have the electrically controlled trans used in Chrysler and DeSoto. But it does have electric wipers where cheaper makes used vacuum.

 

Amp gauge just reads amps, won't care whether 6 or 12 volts, Fuel gauge will need a resistor to drop the voltage, oil and water gauges are mechanical and work fine with the correct adaptor to allow them to fit the GM block......the headlight switch just switches, the original style had an attached fuse so check its o/k, the switch won't care what voltage but a headlight relay is a good idea........my 1940 Dodge runs all the original gauges with a 12 volt 318 Poly, no problems for 40 yrs or so.........andyd.

 

Let us know the details of the swap. Don't know of anyone who has done a V6 but should be easier than a V8, which can be a bear because of steering box clearance. Depending which V6 it could be narrower than a V8, or at least have the option of moving forward a few inches for clearance.

You can take a center tap off the battery for 6V accessories. They are not voltate sensitive except possibly for the radio and it can be converted to 12V by a good radio technician.

 

Thanks Andy! Very helpful!

 

Meeting him today to get more details. I'll keep you posted.

 

The V6 may be the smart choice. More power than the old engine but not enough more to overmatch the suspension and brakes. Easy to fit, and light weight which makes steering and handling better.

The steering, suspension and brakes were state of the art for the times. Repair or replace worn suspension parts, new shocks all around, narrow tires inflated to 32PSI and it will drive and steer beautifully.

 

Sorry, got pulled away with holiday prep stuff and very little garage time. I have removed the old motor, trans, cross member, shift linkage, throttle linkage, etc. Finally got a test fit in today. It's an early 80's 3.8L and I'm getting a new 220R4 from monster in a couple weeks I hope. I'm useing the 200 3 speed he brought for mock up. I got demensions and I'm just using it to get my engine location. I'll wait before I do trans crossmember and mount. I't looks to be a tight fit side to side. Have stock exhaust manifolds. The p***. is fine, but I need a rear dump for the drivers side. Any suggestions? I have to cut the tunnel to go any further. So I'll try to keep you all posted.

 

Cut the transmission cross member out, it's going to get in the way of the new transmission. You shouldn't have to cut the tunnel unless your trying to mount the engine/trans up high. You might have to trim some metal off the inner fenders for manifold clearance. Don't be afraid to mount the engine offset to the p***enger side to clear the steering box, Chrysler did it on just about every rwd p***enger car from the 60's through the 80's

 

Don't be afraid to cut those inner fenders. That front sheet metal comes off, as a unit, with about 10 bolts, makes it much easier to build motor mounts, exhaust, and other things that need to be done. Then cut/trim/modify the inner fenders as needed, and you should be good. Gene

 

The frame, cross member and steering box looks the same as my 1950 Dodge panel truck. But mine is a I beam front suspension. Keep us updated and good luck !!!!!!!!!!!

 

I removed the cross member, and test fit engine and trans. It doesn't appear that I can get it all back far enough and get the engine level enough without cutting the tunnel...I figured I would be cutting the inner fenders. My manifolds are hitting them. I will be doing the offset also. I have the kit from Butch's cool stuff for the trans cross mamber, and Motor mounts.

 

Cool truck! and I will keep you posted.

 

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I was hoping to avoid that as I am alone in the shop. If I have to I will, it would make access easier. Any input on the tunnel cut?

 

I've removed and refitted the front clip on my fargo by myself. Just need an engine hoist or similar and some patience.

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I lift the front clip off my 48 by myself. Pull the bumper, remove the bolts, stand in front of it, grab a fender, pull it forward, do the same on the other side, grab each wheel opening, lift the back over the tires, and slide it to the floor.
If the trans you are using is an OD auto, you will probably have to cut/modify the front two sections of the X frame. Your are probably going to have to make your own trans crossmember, so you might as well get rid of the center X. I suspect that will give you whatever room you need to clear the trans tunnel. The trans tunnel is not a big deal to cut and modify, but I've installed V8s (I did it the hard way, I installed Mopar V8s without any kits) in 5-6 of this era Mopar bodies, and have yet to modify the tunnel, other that a few smacks with a hammer on the left side for head clearance. Gene

 

Thanks all! Got a pretty good trial fit yesterday. Looks like I'll be able to clear the tunnel. Gene, I really don't want to pull the whole clip. I did trim the p***. inner fender, and found a dr. side exhaust manifold that will work so The motor should nestle nicely. I was worried about tilt and the trans pan being too low, but it all looks good now. Also, I do have the trans cross member from Butch so hopefully that'll be easy. It is a 6 cyl. so head clearance NP, and I may get the short WP for fan clearance up front. I know the GM in a PLY thing is not the most desirable, but it's what the customer wants...

 

Yeah, I know I CAN...Just don't want to lol

 

I know that feeling

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lambo .. cold up there ?

 

HA! Wasn't too bad yesterday...-9 before wind chill this morning....Think I'll stay in the house and work on my taxes...lol

 

Well It is in....Mounts for Engine and trans just tacked in as I'm waiting for the correct ****** to get here. Not real thrilled with how much I had to off set it. That steering box is a real PIA!!!

 

The steering box is always a problem as the engine compartment was designed for a straight six, period. The Chev V8 actually fits better than a Dodge and I thought the V6 would give you more leeway as you can move the engine forward if you need to. Did you find moving the engine forward to be an advantage or in other words do you think the V6 fits easier than a V8? I see you offset it to the side quite a bit.

 

I actually set it BACK more. Forward makes the exhaust even harder, plus Radiator clearence becomes an issue. I could use a short W.P. But the exhaust is real tricky with the V6. The V8 has a drivers exhaust manifold available that doesn't drop down too low and has a rear exit (absolutely nec.) The only one available for the V6 drops down real low and hits the box. I went maybe 1/2 inch more offset than the Butch's kit sets you up to do. I extended the plates that the engine side M.M.'s come with, and shifted the mount forward. Killed my Mech. fuel pump possibilities. I don't mind the electric option.
Hope everyone has a wonderful Christmas! I'm going to go enjoy some family time and Christmas magic!

 

I saw a 50 PU at a local car show and it had the neatest firewall. I asked the gentleman how he formed the firewall recess . He said " easy , I used a wheelbarrow and cut to fit . "

 

Old trick. I did one on a jailbar Ford years ago

 

Fortunately I didn't have to do any tunnel mods. Just wish I was doing some steering mods! I've accepted it and moving forward. Sealed up all the holes in the firewall. added new holes for the new heater hoses going to a Vintage air heater unit. Already installed the electric wipers. Removed and repainted the dash. Have wiring to start. Also have to fix someone elses front disc brake swap.....Font brakes plumbed to the rear of the master cylinder with a residual pressure valve?? No Prop valve either...surprising it stopped decent...
I'll post more pics soon. JR.

 

Almost ready for final install. Got the new Trans. in and have to make a couple mount adjustments. Any thoughts on engine tilt? I have 3-4 degrees at the carb pad, but it's more like 7-8 on the cylindr head, or top of valve cover... Seems like too much. Where should I take my measurement from?

 

Couple pics. Smoothed (sorta) the firewall, shrunk the p***. side inner fender....Well, won't let me post pics for some reason...