truck 440
Beautiful truck......heavy truck :D. Do you have the 4.10 gear? If so.....
This comp XE is about as far as i'd go, since you have the bolt on's already.
http://www.summitracing.com/parts/cca-21-222-4/overview/make/dodge
There are some others listed for truck applications, but the earlier intake closing event will help preserve some compression.
Just one opinion, good luck.