41 Plymouth Coupe

[Hardknoxs Motorsports]

New to the group. I have a 41 Plymouth Coupe I am about to start on. Plan for the car is to transplant a newer Hemi in it, and basically upgrade everything in the drivetrain, suspension etc... Was just wondering if there were any people or threads in here of others who have done the same. Trying to research and find the best path possible before diving in. Thanks in advance. 

[P15-D24]

Welcome to the site!

[OUTFXD]

Greets!

[Sniper]

Hello, not sure anyone has put a newer Hemi in one on this site.

 

There are a couple of members here that have done similar though

 

 

[Hardknoxs Motorsports]

Looks like lots of related stuff in there. Thank you for the link!!

[Hardknoxs Motorsports]

@ Sniper do you know of any links/posts about frame modifications on these old coupes. Like frame swapping or modifying  the original frame etc.. to accommodate the small block? Sorry for all the questions. New to the group and swimming around everything at the moment. 

[Sniper]

Thought you were going with a Hemi?

 

 

[Hardknoxs Motorsports]

I am but the best method to do that is what I am seeking input on. Everybody appears to have a different idea. Some say to frame swap it, others say use the original frame and fabricate my own mounts, there's also some that swap the front clip on them. Really just doing my due diligence on what the best most effective method is. 

[Hardknoxs Motorsports]

These old Rigs are very different than anything I have built or modified before so just seeking thoughts from people who have been in there and done it before I jump into it. 

[Sniper]

The two biggest issues with the stock front suspension are the upper shock mounts and the very short driver's side tierod assembly.  Upper shock mount relocation is pretty common and well covered here. Though I found a set of stiff gas charged shocks that fit the stock mounting and seems a good improvement along with cut down Aerostar springs.

 

 

The tie rod issue is probably best solved with a rack and pinion swap as in the first link I posted.  Power steering could be added then.

 

Adding disc brakes to the front is easy, several vendor's have kits, each have issues though. 

 

Rear axle will definitely need replaced which will give you better brakes as well.  Explorer 8.8 swaps are common, several threads here on it and can be had with discs as well.

 

I would not do a frame swap, but I don't weld.  Same with clipping it.

 

Rear suspension will need addressed, I can wheel hop with the stock flat 6 power, lol.

 

[Hardknoxs Motorsports]

Right on. I do weld but have been leaning more towards just using the original frame and just making the adjustments you mentioned. Seems to be the most cost effective way from a time and cost stand point. Any ideas on what some are doing as far as the engine and trans mounts go for the small blocks? I heard of one place called Butches cool stuff that made a kit for them but they recently closed. I will have to fab some for sure but looking for ideas along the way. Plan to start on it first of the year so I am just gathering ideas right now. 

[Sniper]

Butch's kit left a bit of engineering to do. 

 

I would go with a universal engine mount brackets similar to these

 

https://chassisengineeringinc.com/product-tag/dodge/

 

They also make universal transmission mounts, but if you look at the offerings you could probably fab something up easily

 

https://chassisengineeringinc.com/product-tag/universal/?category=engine-transmission-crossmember

 

Your biggest issue will be the exhaust clearing the stock steering box is you keep it.

Edited December 1, 2022 by Sniper

[Hardknoxs Motorsports]

Will likely discard it and go with the rack and pinion. Thank you for the leads on those parts though. Will post as I go and am sure will have other questions.

[Marcel Backs]

One of the smaller displacement late 50's hemi motors may  be a better match for the narrow engine bay in that beauty. A well done up one of those would be eye candy to anyone checking under the hood! Is she a 3 or 5 pane? Welcome to the site. M

[Hardknoxs Motorsports]

I've seen the newer Hemi in them so it's possible. I will agree it's tight but it's possible. You'll have to educate me. What do you mean by 3 or 5 pane? Excuse my lack of knowledge lol this is my first one from this era. Here is a side shot of it. Plan to leave the body as is. Patina is perfect on it. 

 

[andyd]

Hardknoxs...welcome aboard.............I havce owned my 1940 Dodge sedan since 1971, I installed a 318 Poly in 1973 & auto...the car has the original lower A arms, 41-54 Cast steel MOOG upper A arms, 41 stub axles, 1" heim jointed adjustable sway bar, mid 50's Ford Coil springs, relocated upper shock mounts and 11" vented PBR Oz disc brakes with a 9" narrowed Austin 1800 Rack & Pinion, rear end is stock semi elyptic springs, heavy duty shocks, 1991 Oz Ford Falcon disc brake rear axle, stock body with 2 widened rear fenders, custom made Alloy steering column using Valiant upper, bucket seats etc etc..........have attached some pics or the 40 Dodge & 41 Plymouth I had for a while....it was to get a 230 & 5 speed , finned head, etc............so...........

 

............my suggestion would be to upgrade the stock front end with better shocks and/or relocate the upper mounts, swap in a thicker sway bar, use a centre steer rack to reduce bump steer.....check out various engine mount kits that use early Ford biscuits & chassis mounts or modify the original Hemi mounts to suit.........but don't go swapping  the chassis, these cars use a better engineered frame then early Frods or GM stuff and just need some basic upgrades.........if you want more info ask away........regards from Oz.......Andy Douglas  

[Hardknoxs Motorsports]

Those are beautiful rides and thank you!! I will certainly be reaching out!!!

[Hardknoxs Motorsports]

Those are beautiful rides and thank you!! I will certainly be reaching out!!!

[allbizz49]

Nice sedan. Where's the coupe?

[Hardknoxs Motorsports]

Is a 2 door not a coupe? 

[andyd]

Technically no, the car you have is a 2 Door Sedan....nothing wrong with that tho'....the red car that I pictured & owned is a Coupe.......in 1941 they, mopar had 2 versions of the Plymouth Coupe, both used the same basic body shell like I had.....most were called Business Coupes and used a single split bench seat like what your 2 dr Sedan has and no back seat.......the more uncommon version still used the "Coupe" body shell but also had a pair of small folding rear seats behind the split bench seat and were called Auxillary Seat Coupes,.........my car was in fact that type.....I have attached a pic of the rear seat setup that my car had & yep was RHD, really suitable only for children tho' adults can sit there.........then in 1942 Plymouth came out with 2 body styles.....the Business Coupe using the same body shell as 1941 and a longer roof Coupe called a Club Coupe with a full sized rear seat.......both body styles continued to 1948...........but the 2 Door Sedan as your car is was always available and used a full sized rear seat behind the folding split bench front seat.............again.....there is nothing wrong with your car........to be honest the 2 door sedan is probably the more uncommon compared to the various Coupes or 4dr sedan...............works for me..........Andy Douglas   

[Hardknoxs Motorsports]

Thank you for pointing that out and the education. I didnt know that. 

[Sniper]

Basically the greenhouse makes it a coupe or a sedan.  Andy's ride has a smaller and sportier greenhouse and is a coupe, yours is much larger.  Then there are club coupes like my 51 which sort of split the difference.  I won't get into the "four door coupe" some people try to foist off on us.

[Hardknoxs Motorsports]

Definitely goes beyond what we traditionally think of a Coupe and Sedan.  

 

Edited December 2, 2022 by Hardknoxs Motorsports

[greg g]

2 door sedans were pretty rare birds.  Not many made, fewer left.

Edited December 2, 2022 by greg g