56, 420, 5 roller 4 spd

[Lavoy]

It will bolt up, you will need to change radiator, hoses, throttle rod bracket, fan, fan support, not sure what belts you are going to need, and other stuff I am forgetting about. You will also be really disappointed in the power compared to a 420.
Lavoy

[theshanmand1!]

Good morning all.
Thanks Lavoy for the info.
Well, im still on the fence, partly… but leaning towards just doing a rebuild on the 420 engine. That will be down the road a bit as my dance card is full with priority projects at the compound
Lavoy, i will be in touch for more of your very much appreciated knowledge.
Thanks again to all on this platform!
Have a great day

[RacinJason]

My Frankenstein '57 420 came with a 40C engine. Fits, tho radiator hose and, I think, air cleaner hose diameters are different, maybe a couple other minor differences. The distance from front of the engine to the radiator is different, I can't remember all the details but should be a fairly simple swap. I'm sure others can give better details.

[dtoots1]

Believe i have about $1000 in rebuild on my 420...course it had to be sleeved cause #2 cylinder had crack in it...and hard time getting new crank bearings..dont know supply now. also had valve job done while out..runs great tho, so aint complainin