I've gone 12's off of a mechanical fuel pump and factory 5/16 fuel line from the factory tank with no issues.
I've never tried the hughes eccentric (or magnum swap for that matter). Owned tons of LA's and lots of magnums,but never swapped. Going to, though, at some point. Have a 318 magnum/eddy RPM intake sitting in storage.
If you can get a '89 - 91 LA360 cam, they will have the fuel pump snout. They are roller cams, so they work and you'll gain about .030 lift as they are ground for the 1.5 rocker instead of the magnum 1.6. I have this cam for my "eventual swap".
