Today, dollar for dollar, is the 318 faster than the 340 ???

I don't know $3000 would still be limiting a 340 I think? Unless you already had some really good X orJ heads laying with the 340 block.

The smaller 5.2 magnum needs less head . And responds great to bolt on mods. Heck do a $3000 forced induction setup on a 5.2 magnum and see 400hp with the right valve springs