318's were put in all sorts of Exotica such as Dusters, Darts, Scamps, Coronets, Belvederes, Fury's, Demon's, pickups, vans, Volares, Grand Fury's, Diplomats, Fifth Avenues.
I love how they are still very obtainable....and cheap because people only want cubic inches and not plentiful parts.
I would use a Roller Cam block and reuse the factory cam or get a custom grind from Comp Cams......my last 318 build I got a roller that was 228/230 @ .050", .520" 112 for $285.00
Cloyes Double Roller Timing Chain.
Freshen up the 302 heads with some 1.88/1.60's and new hardware.
Edelbrock Performer with a 650 holley and your all set.
Check this out...I read that you don't want NOS, and you want to stay all motor but....this is what I would put your $1500 towards:
http://www.thesuperchargerstore.com/Mopar.html
Would make a nice little runner for chump change.....when it throws a rod out the side of the block (if it ever does)....another long block is only like $100-300 away!!!