As far as engines, the DeSoto Hemis were physically smaller than the Chrysler Hemi's and the Dodges were smaller still.....but they are all wide and heavy. Chances are your choice is actually going to be based on what you able to find. You might want to skim these posts I made a while back to get an idea on the engines:

http://www.clubhotrod.com/forums/showthread.php?t=15088

http://www.clubhotrod.com/forums/showthread.php?t=15089

http://www.clubhotrod.com/forums/showthread.php?t=15090

http://www.clubhotrod.com/forums/showthread.php?t=15091



Before you read on, I am not trying to talk you out of this project, I personally think it would be a neat one. I do want to give you an idea of what your getting into however.

When doing a major swap such as your contemplating (especially on an earlier cars such as the 53) it is a bit more complicated to end up with a safe and fun car to drive than simply dropping in a bigger engine.

Yes back in the 50 and 60's that was about how it was done, but rodding has come a long way since then, as well as our expectations for safety and performance. It's pretty easy to look at a car and say gee, I think I drop a BelchFire V8 in and be the terror of the town, but the planning process NEEDS to be a lot more comprehensive.

In the case of this particular swap, your planning on adding a LOT of additional weight on what are 53 year old suspension components and likely stopping with brakes that were marginal (by today's standards). Often when you get to that point it often starts looking like a front suspension swap is also going to be a best alternative.

Then of course there will be the downstream changes that will be necessary to actually make the car move, upgraded cooling system and things like transmission and rear-end choices. Generally speaking these are not simple bolt in changes often resulting in a car that can never be economically returned to stock.

Then there is the time and cost factors:

Of course there is the cost front end upgrades. it is possible to convert these front ends to disc brakes and described in one of Tex Smiths books, but it is very labor intensive, and you will still have the handling of a 53 Plymouth, likely worse due to the added weight. A front end conversion can easily run anywhere between 1-5 K.

You've also picked a very expensive engine to build. After initial purchase of a buildable engine, you're still looking at around $5000 on a non-performance rebuilt (I just finished a 331 and can attest to this). Then add things like trans adaptors etc it starts adding up to a pretty pricey project even if the paint and body work and upholstery is currently good.

Time to do a project like this will likely be measured in years instead of months unless you have the ability or deep enough pockets to work or pay for work to be done on a continuous basis (20-40 hour weeks). If you have equipment and place to work on it and do it a few hours a week, chances are your looking at a minimum of 2 years on a project like this one could turn into.

This is doable (anything is with enough money and time), and if you have the dedication to see it thru it can be a very neat project.