Early Dodge Hemi w/Plymouth Parts?

I was reading the winter 2007 issue of the HRM Archives Series, this issue is dedicated to Hemis, and there's a caption in the picture of the Markley Bros (Bob & Charley) belly tanker claiming the tanker was powered by a "destroked, 253ci '55 Plymouth bottom end with Dodge heads". Claims to have reached 280 mph at Bonneville.
Also, there's a photo caption for a Digger claiming to run a bored 240 ci Red Ram w/'55 Plymouth pistons.

I'm always looking for speed tips for my 270. What's the advantage of using Plymouth parts with early Dodge Hemis?

I found this on the 241: "The 241 was Plymouth's non-hemi version of the 241 Dodge Hemi for 1955. Bore and stroke are the same at 3.4375” (87 mm) by 3.25” (83 mm). The block is the same block for all 1953-56 Dodge 241 and 270 polys and hemis, and also the 1955-56 Plymouth 241 and 259 polys. So the heads, intakes, water pumps, and oil pans all interchange. The exhaust manifolds do not. Given a good set of Dodge 241 or 270 hemi heads, these can be bolted up quite easily to the 1955 Plymouth 259 making a Plymouth hemi with P27 engine numbers and original Plymouth intake and carburetors."

Does all of the above apply between the Dodge 270 and the Plymouth 270?

Kreepea

 

The difference between a low deck Dodge/Plymouth Hemi & Poly is the complete head assembly, including pushrods, pistons. I've heard conflicting info on the intakes. People did convert 259s to Hemi to race in the under 260 class, not sure why someone would destroke to 253 though.

 

Supposedly the Hemi & Poly blocks are exactly the same, but there have been reports of pushrod clearance problems were they go through the block when Poly blocks are Hemied. Hemi pistons have valve reliefs opposite each other, Polys have offset reliefs. To convert a 259 they had to use custom pistons or machine the Plymouth ones.

 

Markleys were blown on nitro. I would bet they didn't need valve reliefs in thier pistons. They later went 290 with a 290 inch motor and not to long ago ran 360 in a streamliner with a 300 inch DeSoto. I would bet the 253 number is a typo.

 

last wed i sold some red ram stuff i had fo 20 years . it was given to me. any way 54 block punched out to std 270 bore also std desoto. it adj rockers dimple valve covers when he picked it up he had another in the truck with the same upper end 3-twos side mounts prob 325. all in one day. he is a hemi collector from stockton cal. henry hernandez shop 209- 462-6254-- cell- 209-609-7095- buys sells.

 

One of my plans for the '55 270 is put the heads on a '56 270 poly so that I'll have a motor with eng mounts on the side. Sounds like there may be more to it than just swapping the heads.

Kreepea

 

The original question was why use Plymouth pistons. The answer is the 55 Plymouth 259 had a slightly larger bore than the Dodge 241, and going to the Dodge 270 would be going too far. Here's my P27 Plymouth with Dodge hemi heads, bolted right up, started immediately, runs fine. Richard

 

Thanks, rbmain!

 

Hi there, I have a 241 Dodge hemi, and a 315 poly V8, which I will get some 315/325 Dodge hemi heads for and new pistons with opposite valve reliefs, for the 241 I have a rare Edelbrock 4 barrel manifold and WCFB Tea pot carb with 1956 Cad air cleaner-oil bath, and for the 315 I have a Offenhauser 2x4 carb manifold and two mechanical WCFB carbs with air valve plates (came off 265 Chev (I think). Also for the 241 Dodge hemi I have a Spalding twin coil "Flame thrower" distributor and RED RAM Valve covers, also have a Offenhauser 3x2 with 97's, Eelco progressive carb linkage and D500 valve covers, always looking for early Dodge hemi vintage speed equipment!

 

...Hemi heads have the looks, but the Poly heads make similar power in most applications.
For those who like something a little bit different, we now have forged pistons available for the Poly heads....

.

 

Polys heads are a interest to me, I saw an article in Australia where Allan Fontain makes new finned valve covers for them, only two bolt valve covers, the Edelbrock finned alloy valve covers had three, also they talked about a stroker 360 LA crank shaft being able to be fitted to th 313/318/326 A series poly head motors, to be a stroker 400 cu in!!!!!
Wouldn't that wake the neighbourhood up , especially if your add a 671 GMC on top! There was a speed shop owner in Australia called Eddie Thomas who had a front mounted 671 in early sling shot dragster! I have the article if you want me to send to you? keeping the Firepower lit!

 

Hi there, 53 & 54 Dodge hemi's and poly's have no side engine mounts, 55 and later (259 &270 ) have the side engine mounts, so most likely 259 and 270 Plymouth's & Dodge's have simillar casting, althought the Hemi's are different push rod hole configuration, also head gaskets differ from Poly to Hemi, & I think from memory Exhaust push rod lenght is different, but don't quote me on this part. Hemi pistons have valve relief 12 oclock for intake, 6 oclock for Exhaust, Poly's are offset as Poly valves in slightly different place in head, if using low compression pistons you may get away with it, haven't tried this swap myself.

 

There is a Thread on the "A" polys here, somewhere.