Welcome to FBBO from NorCal Sierras
I think budget & your actual automotive background,
knowledge &/or you fab skills, is the biggest issue
you can do a lot with the 383,
easily double the hp output
you could do a 440 swap easily too
you can do a lot with a viper v-10 combo too,
if you have the skills & $$$$$$$
you can do the efi on any of them
call
@fastmanefi he also a member here
check out Schumacher Creative Services
http://www.engine-swaps.com/
Check out Mancini Racing
http://www.manciniracing.com too
Check out 440source, check out the made in USA products
or the stroker kits or tech articles etc.
http://store.440source.com/
good luck