Is there any difference in the ve engines and the newer p pump engines? Is the cam cylinder head valves springs and everything the same? If not is everything interchangable without major modification? I might start building an engine

 

For the most part everything is interchangable. The head castings were improved on the newer engines. The cams are slightly better on the newer ones. Non-intercooled 1st gen heads have 9mm injector bores and are more prone to cracking. In order to put a p-pump on a 1st gen engine you have to change the timing cover. I know theres more that I am not thinking of right now.

 

heres a lot of info...

http://dodgeram.org/tech/dsl/Facts/epa_changes.htm