Early Hemi vs. Poly which is less hassle?

Subject pretty much sums it up. I'm starting to plan future upgrades for my 53 Plymouth. I'm wanting to use either an early Hemi or a Poly (they're both cool). What are the pros and cons? Is one easier to get parts for (ie. less expen$ive that the other)? Or should I maybe just keep the flathead 6? Thoughts?

Thanx!

 

Hemi, hemi based Poly, & late Poly are all cool. Just a matter of which you find first, or decent price. The late Poly will be the cheapest core, parts ain't cheap or any. Flip a coin on 'em. Do a search, lots of info.

 

Poly has far cheaper valve gear to replace, less leaks - no spark plug tube seals. Weighs less, narrower (but not narrow). Pistons harder to find but pretty cheap. Exhaust harder to find.
Poly motors are cheaper to buy, biggest poly is 1958 Saratoga 354 - 310 hp (below). Easiest poly to find and get parts for is the (non-hemi) poly "A" (318, etc.).
May not be important to you, but the earliest poly is 1955, so it's not something a dealer would have done when new (but all of the hemi families were on-line in 1953).

 

OK, so basically they're all gonna be pricey so pick my poison and have a good time! Thanks guys, that's kinda what I thought!

 

With either engine it depends on how complete it is as to cost. If it is complete from carb to pan at least you don't need to hunt down original parts to start with. There are plenty of new parts for the Chrysler hemis so that is what I would start with for a build. I did a 392 and it was a long block buy so I had to find all the missing parts or buy new parts that were available to replace them.

 

The 318 Poly actually isn't any more pricey than an LA 318... and uses most of the same parts, save for valvetrain and heads.

~Jason

 

Cool thread here.

 

In 1962 I installed a '55 Dodge 270 Hemi in my '53 Plymouth Convertible. Had to move the steering box to the left to clear the starter....did that by notching the boxed frame and adding a reinforcing plate on the outside of the frame rail. Worked pretty well. Stock radiator cooled fine etc. Later I attempted to install a '56 315 Poly, thinking it would be a 'snap' since the poly heads were narrower than the hemis. Not so fast! The poly heads/exhaust manifolds actually interfered with the steering column more than the low block hemi.

I should also state, before this successful swap (the 270 hemi), I had tried a '51 Chrysler 331 and semiautomatic. Actually got it operable, but it was such a compromise, for a lot of reasons, took it out and replaced the original 6 until the '55 Dodge came along.

In any case, if you use the stock frame and steering, be prepared for some interference. If you do something like a Fatman frame stub, almost anything will fit.
BTW the '53/'54 Dodge hardtop, convertible and wagons used essentially the same body (inner structure, doors etc,)as the Plymouth but the front of the frame was redesigned enough to accomodate the 'baby' hemis, the size of which is the same as the 270, the 315/325 are raised block versions, therfore a bit wider/taller, but the same length.