More intake selections
More piston selections
More head selections
More rocker selections
More valve selections
More cam selections
Smaller mains = less drag, more power
(OK, I even think that's crazy but it is true though you would never feel it.)
The following can be done one way and not the other.
Head swap between LA and Magnum not a problem.
LA can use a Magnum head, Magnum can't use an LA head.
Stronger valve train set up.
LA to Magnum cam swap easier. Magnum to LA cam swap not possible OR you'll need a. Entire LA front.
I myself like the bigger bore though someone said very accurately you'll never feel or know a .040 larger engine. That's OK, the dyno will show you and the drag strip will show everyone else with all other things being equal.
But this is what I would do with it all. I may sound like a hypocrite, so here it goes, while I did t have the choice the OP has, I just recently raised a '00 Magnum 5.9 for my B body build and swapped on bolt on parts for the power plant.
Current I have a 340 block at the machinist for a check up for a 4.25/W5 stroker engine.
A 360 & a 5.9 in the wings slated for a 4.0 arm upgrade.
And 1 - 360 awaiting a W2 set up to be done.
In the end, what ever your happy with.
Money wise, if your pockets could use some help, and who's couldn't use some, sell the 340 and roll the money over into the 5.9.
