Making power out of the 318
I know the original post said 318. 3K budget and 400HP goal, I'd say start with 5.9.
I'd like to build a 318 for fun myself, I get tired of hearing hearing Frod & Chebby guys griping 302 and 305-whats mopar got, gotta go so much bigger, thats cheating.
Hell, I'd also like to do a Slant.
But reality says for 3K, A Magnum right from the yard will probably even still have good hone marks, not be all clapped out, & just need some add-ons, & a lot less work.
You gotta figure Trans, Brakes, & suspension too. I know thats not in the 3K expectation, but you need to be taking care of that stuff too.