Yea, the old work around with what ya got. I get it. Been there done that. It is what it is. It’s not like these parts are candy store cheap as well as not having deep pockets to throw money at the problem, perceives or real, like the U.S. Government does at its problems. (Real or perceived!)
The smaller cam - 220/108lsa is what I’d use and (again) have for a 360 in a ‘79 B body that has 3.55’s spinning 245/60/15’s. The converter is a 2500 in a 727. The Magnum is a bit lighter than delivered, not much. It’s Reggie says 3675lbs. IIRC. Is super close to my ‘73 Cúda in weight. The B body is loaded with everything except a moon roof.
If I was in your shoes, I’d build it as is and perhaps if it isn’t performing the way I would like it to, the converter is probably the item I’d choose to adjust. That’s only one part (though a chore) to swap out.
