Mopar Forums - 1963 Plymouth Belvedere 318 Poly Motor Swap

Hello,

I have 1963 4 door Plymouth Belvedere v8 318 Poly motor push button automatic that I purchased in middle school and rebuilt with my father. This car ran great for about 4 years until several issues poped up (Engine overheating, idle speed, fuel issues). Since then it has sat for about 8 years.

My father has since moved may states away, so his expertise is not an option
I do have some local friends who have experience with old mopar's
My experience level on combustion engines is about 3/10, but I am able to follow a manual pretty well

I now have the time and money to spend on the car and have ran into a lot of problems (I do own the full shop manual)

Parts parts and parts. I did not realize that the Polysphere carbs and intake are not interchangeable with the more common LA motor.
- I have 2 Bendix Stromberg carbs and have had issues finding rebuild kits that fit...I appear to not be the only one with this issue.
- I'd like to change the intake and just plop a Holly or Edelbrock carb, but the last aftermarket intake for a Poly stopped selling several years ago...so no hope there unless i want an ebay over priced used and damaged one
- Overheating was an issue when I was in high school and i'd imagine it was still an issue today if I could get it running on these old Carbs.

With all these issues in mind (and maybe others), I was told I should just rip out that old 318 Poly and put in a 318 LA or even a 400+ Hemi.

Is this a solid solution or even possible for my year and version?
- If so, what year and size does anyone recommend?
Am I able to do this and keep my current transmission?
Am I leaving any obvious questions out? Am I crazy for wanting to keep this car and possibly drop money on it?

I appreciate any help people can provide. Criticism is the key to learning...so have at it!