Projects 55 Plymouth 3 speed manual transmission bellhousing adapter needed

I recently found my old high school car, a 1955 Plymouth Belvedere with a 3-speed manual transmission. The engine was shot, so I am having to replace it with a more recently built 318 that came out of a 1968 Dodge coronet. I was wondering if anyone could tell me if anyone makes and/or where I can get an adapter plate to mount the 1955 Plymouth 3 speed manual ****** to a 1968 318 engine's manual 3 speed ****** bellhousing. The bolt pattern for the 4 mounting bolts don't quite match up. Any help would be greatly appreciated.

 

Going the wrong way. most all adaptors are for putting newer ******s behind older engines. Just get a ****** for the '61 &later LA engine.

 

If I were in your position, I would consider a full synchro 3 speed from something that would directly mate to your 318, like @George said.

 

My, how things have changed over the years. When I was young, the main purpose of transmission adapters was to put newer engines against older transmissions (in older vehicles; an OLDS "Rocket" against a '32-'48 Ford transmission, for example).

In this case, I agree with "George"; in using a transmission that fits the engine. Not only will you have a much better transmission, but better parts availability. I haven't tried to find any '55 Plymouth transmission parts lately, but I'll bet it wouldn't be any fun.

 

Plus, it would be one of those "selector" type mutations, and not very strong either. Your car's got an open driveline; take advantage of that and upgrade your transmission at the same time.

 

Oh yeah. Try getting a floor shift for one of those. If you're still leaning that way. I made a very simple, effective shifter for a '55 Dodge selector box in a "T" bucket I once had. If you want, I'll let you in on my "secret".

 

Wait a second! If he replaces the original transmission, what's he gonna do for an emergency brake? Now, to do it right, he has to change out the rear end with one that has an emergency brake. Project creep!

 

The other issue is the brakes, very few options for replacement brake drums. So replacing the rear end fixes that issue.
What are we going to do with the front? .... Looks like a disk brake conversion for the new horse power & speed. .... & a 2 stage master cylinder ..... project creep.

 

I ***ume he wants to keep the column shifter

 

Do any of them match up? If 2 of them do put them in and do a crank to centering on the bellhousing trans hole. If you can get it with in .003” even elongating the holes a bit; drill in 2 guide pins and elongate the others to fit. I do it with every engine to bellhousing fit up to keep the trans from popping out of gear.
My guide pins are usually 1/4” or 5/16”. I’ve never had a problem. And these are circle track engine/trans combos that we beat the hell out of them.

 

The column shift mechanism for a selector transmission operates much differently that a regular three speed. A change on transmissions probably will require a change in steering columns.

 

This is the big question, sometimes the bell housing can be re-drilled to bolt the ****** to it.
The length of the output shaft, the pilot shaft bushing inside diameter. .... The throw out bearing that fits the bell housing aaaaand the output shaft of transmission?

Be really easy to suggest to modify the bell housing to fit .... All the mechanical's inside the bell housing have to work also.

Who knows, drill new holes & it may work .... chances are you need more fabrication then a adapter.
A modern trans to fit the engine would be the path of least resistance imho.

 

Damned Mopars anyway....

 

Rather then mess with a bellhousing to match up the original trans, I would think a ****ter shield would be easier. you could find your needed center to align with the clutch, and drill new trans mounting holes, and weld whatever nuts you needed on the inside. You could also adjust for any conflict in the transmission input shaft to 318 crankshaft depth issues with a steel ****ter shield too.

Plymouth used the column stick shift levers up through the early 60s, might be possible to find one of those transmission/shifter setups that might match the 318's bell.

Personally, I'd upgrade to a floor shift 5 speed and a modern rear axle (to get away from those old rear drums) with your e brakes on it. You can probably adapt the Plymouth's e brake mechanism to operate the modern e brakes. If the Plymouth's front brakes are still good, a disc brake upgrade might not be needed, but if the Plymouths front brakes need replacement, a disc conversion is likely cheaper then replacing the original 55 Plymouth stuff.

 

Isn't there a post going on a transmission issue on an early 60s Olds? That guy can't even put a modern transmission on his motor.
Any time you try to mix old stuff with new stuff, challenges happen. Its not usually just a one brand issue, its pretty much across the board. Project creep is a hot rod issue.

 

I think that if it were mine, I'd be looking for an early Plymouth or Dodge Poly or Dodge Hemi.

Now we got more style and fewer problems. If the LA is any good, it'd probably go a long way towards another engine.

 

Those are out there, but we're talking Mopar in stead of Ford!

 

Was the original engine a 6 or V8? The older 8 clutch housing may be adaptable to the 318. www.qualityengineeredcomponents.com may be able to help. He is a member here but I don't recall his user name.

Also, if the front bearing retainer OD of your trans fits the later housing's pilot hole, one should be able to drill and tap the mounting holes. If not, maybe a locating ring can be machined.

I just completed a similar thing, A833 to a 60 Dodge truck housing on a flat six. Required some welding, old bolt hole plugging, drilling etc, but it seems it will work. Not in the truck yet but ***embled on the floor.

Edit: forgot one issue, the length of the main drive gear. Some early Mopar stuff had really long ones. Some can be replaced with shorter ones from later models of the same basic trans. Wasn't a problem in my case.

 

Sneaking over on Alapar I came up with this tidbit that rather clarifies things.
This is the work by one of their members RonStafford55. There is a lot of info that is not of use here but when you scroll down to A/LA/Modern Hemi Pattern - you find the info you are looking for. The earlier 318 bellhousing should bolt to the later engine. I've got a 56 Desoto Hemi in the shed that came with a 3 speed overdrive and complete clutch and bellhousing that I thought if I ever put it in something that I would run a Torqueflite behind it instead and I also have an 85 Torqueflite out from behind a 360. I did a bit of homework back ten or so years ago to see if they would bolt up and work.

Engine bellhousing patterns:

• Chrysler Extended Block Pattern - 1951-1954 331 in³ industrial-use Hemi V8
• G/RG Pattern - G Engine (Slant Six) 170, 198, 225
• B/RB Pattern - B/RB Engine 350, 361, 383B, 383RB, 400, 413, 426 Wedge, 426 HEMI, 440, aftermarket 472, aftermarket 528
• A/LA/Modern Hemi Pattern - 1950s-1967 Semi-hemi A-series 241, 260, 270, Plymouth A-series 277, 301, 303, 313, 318, Red Ram A-series 326, LA Engine 273, 318('66), 340, 360, 238ci(3.9 LA) aftermarket W2 program, aftermarket 408, Magnum ('92+) 5.2L, 5.9L, 3.9L Magnum, 8.0L V10, 8.3 V10, 8.4 V10, 3.7L V6, 4.7L V8, 5.7L V8, 6.1L V8, 2.8L CRD Turbo Diesel
• need pattern name, if any - Chrysler K engine 2.2L, 2.5L I4
• need pattern name, if any - Chrysler Neon/Powertech engine 2.0L, 2.4L I4
• need pattern name, if any - Mitsubishi 2.5L V6, 3.0L V6
• need pattern name, if any - Apparently not the same pattern as LA 2.7L V6, 3.2L V6, 3.3L V6, 3.5L V6, 3.8L V6, 4.0L V6 (maybe on 3.3 and 3.8)
• need pattern name, if any - ***mins 5.9L 12 Valve Diesel, ***mins 5.9L 24 Valve Diesel, ***mins 6.7L Diesel
• Chevrolet V8 Pattern - GM Iron Duke 2.5L I4 used in AMC/Jeep 1980-1983. Chrysler 904 was produced with this pattern
• GM Metric Pattern - AMC/Jeep 2.5L I4, GM 2.8L V6 in AMC/Jeep. Also called GM 60 Degree Pattern
• AMC Gen II/III V8 - 88-99 Jeep 4.0L L6, AMC 290/304/343/360/390/401 V8 and any 72 and later 232 L6 and 258 L6, Gen II 326 V8
• AMC Gen I V8 - AMC Gen I

Transmissions with cast-bellhousing patterns, rear wheel drive:
Chrysler A-727/36RH/37RH:

• G/RG
• B/RB
• A/LA/Modern Hemi
• AMC Gen II/III V8
• GM Metric Pattern? - Dakota in '96+ with AMC 2.5L I4? Other legacy Jeep/AMC?

Chrysler A-904/30RH, A-909 (904 with lockup TC), A-998/31RH, A-999/32RH:

• G/RG
• A/LA/Modern Hemi
• Chevrolet V8
• GM Metric Pattern
• AMC Gen II/III V8

A-518/46RH/46RE:

• A/LA/Modern Hemi
• any more?

A-500/42RH/42RE/40RE/44RE:

• A/LA/Modern Hemi
• GM Metric Pattern? - Dakota in '96+ with AMC 2.5L I4?
• any more?

A-618/47RH/47RE/48RE:

• ***mins applications need name of pattern
• A/LA/Modern Hemi (for Dodge Truck iron V10)
• any more?

45RFE:

• A/LA/Modern Hemi
• any more?

545RFE:

• A/LA/Modern Hemi
• any more?

68RFE:

• info?

Transmissions with cast-bellhousing patterns, Front Wheel Drive:
A-404:

• need info

A-413:

• need info

A-470:

• need info

A-670:

• need info

A-604/41TE/41AE:

• "573" cast into bellhousing for 2.5L (presumably K engine)
• "631" cast into bellhousing for 3.0L (presumably Mitsubishi V6)
• "577" cast into bellhousing for 3.3L Chrysler V6 Possibly same pattern for 3.8L V6, 3.2L V6, 2.7L V6, and 3.5L V6.
• need more info

A-606/42LE/42RLE:

• need info

40TES/41TES:

• need info

62TE:

• need info

ronstafford55
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55 Plymouth Belvedere, That info came from this site : They have specific sections for just about any Mopar interest with a Hamb Quality knowledge base. Allpar Forums

The older mopar ride section is here All other cl***ic cars | Allpar Forums

 

The early V8 and 318 have several bolts in the same place the locating dowels are different . The big issue is the early crank sticks out farther than the 318 making the transmission imput shaft to short for the 318

 

If I remember correctly going back to my first car, the OP will lose the e-brake function. TheU-joints are ball and trunnion types so the drive shaft would also need replaced or be modified for a different trans.
I like the idea of a steel ****ter shield rated bellhousing, and re-drill for the application.

 

• Yhis is wrong. The hemi, hemi based Polys & A Polys up through '61 are the same. '62 & up are different bell & crankflange.

 

"73RR" Gary's a great guy.

 

Good catch George, and Thanks for the nod.
I really hate to see such mis-information 'out-there' in the nether regions since someone might actually rely on it.
Now, we are up to 23 replies and the OP is absent. Perhaps he thought that early Mopes were easy.....

 

Can you get the whole Coronet and swap the whole drive train?