73’ 318 dies under accel with new intake & carb

Bewy said

RRR,
I will lend you my glasses. Post #9. Man VA 'will cause a bog'.
And totally wrong to say a switch to MVA 'REQUIRES' a change in initial timing because in this case the OP has told us NOTHING about his combo other than it bogs.....
For all we know, the diaphragm in the VA unit is ruptured, with NO vac adv being applied, but causing an air leak....& bog. Just one of many possibilities.

Click to expand...

Yep, that's what I said, and I stand by it.
I didn't say you ALWAYS use ported vac, it depends how you set up your engine, what ignition you're running and how you dial it in.
His is bone stock. Using manifold vacuum in this case WILL make it bog.
What I DID recommend is that he use ported vacuum because that is what the factory used, and he didn't change a SINGLE other thing other than the manifold and carburetor. His ignition is set up to run ported, and unless he changes a bunch of other things that I won't get into here (because it's not relevant to his issue), it won't perform properly.
Now, there could be other issues contributing to the problem, as others have pointed out- but it's certainly a contributing factor in his case.