ok - based on the intel in the link below (culminating in the below dyno specs), I've decided to go with a nice simple set of '73 A-body 318 manifolds on the warm magnum 318 going in our Demon

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/3149775/340-manifolds-or-magnums.html

Bottom line: Using a 360 crate engine, there is very little difference between 318/340/360 manifolds (or even headers), and since I am not doing headers the decision is even easier - only 7hp/9 lb/ft difference b/t 318 and 340 manifolds (and just 16hp/25 lb/ft difference between 318 manifolds and the best TTI headers) - no where near enough to be remotely 'bothered' by, and 318 manifolds 'match' the magnum ports much better than the 340s, so 318 manifolds it is...and I already have 'em



318 above, 340 below -


- Sam