The big block flathead 6 engines from Crashlers, Desotos, and industrical, agriculture applications are two inches longer than the engine in your Plymouth. A few modifications will be required to install one in your burb. But is is doable. I instsalled a Desoto 251 CI engine in my 48 Plymouth P-15. I have dual carbs, dual exhaust, dual points in the distributor, a 270 degree duration camshaft, coupled to a T-5 transmission, and pushing a 3.55/1 Dodge Charger differential. I have taken my car on several extended road trips and it has never let me down. I can run 70 MPH in 5th gear with the engine turnig 2000 RPM's. Pulls the hills well as the engine has lots of torque. For pictures of how I did this visit my Photobucket album.
http://smg.photobucket.com/albums/v65/DonCoatney/ Make sure you view all of the sub albums. Any questions ask away.
Don Coatney
