Go 390 stroker they make super impressive motors with correct parts. My darts 390 consists of a '71 318 block scat cast 4" crank scat H rods custom ross 9.5 blower pistons hughes hyd roller retrofit setup. Heads are Indy lax that flow 284 @ .550 w/ 2.02 1.60 and procomp airgap knockoff intake. Also has the awesome PRW. 1.6 Stainless roller rockers. This assembly was worth 457hp @ 6300 and 488 tq @ 4400 at the wheels. My buddy built a 360/414 shortblock same comp, heads, cam, intake, rockers he only bested me w/ 461hp @ 6300 and 490tq @ 4400 at wheels. Great motors but not much more for a ever harder to find '72 360 block which he paid $250 for when '67 to '75 318's are all but free like mine was cast was given by a local bowtie enthusiast. That bowtie boy aint real happy about being patty slapped by his cast away 318 from that rotted out powerwagon he scrapped.