My Blown 340

do you have no suports from the plate to the top area of the intake???
ide call and see what they say about support and repairing that intake,,
lots of guys run the belt to tight they like the wine from the belt,,but to tight can also break the front of the crank shaft off,, unless you are a good aluminum welder,,or know of one,,,

No there are no supports,just this adapter welded to the cut down manifold

In his video he is calling for 1/2 slack to each side of neutral for the belt...I don't recall how tight or loose I was running the belt at that time.