i would think the real issue is building for 5300lbs and 3.23 gear. what are the goals? i don't think there is one correct answer for the question of manifolds.
It might be difficult to believe but there's more to life than drag racing. This is a plus-sized cruiser that is the perfect candidate for silly amounts of torque. Think of the Mercedes S65 AMG. A 5.5 liter twin turbo V12 cranking out 635 hp and 720 lb/ft in a 5300 lb sedan. Why? Because they can.
I'm building it because it's my car, my engine, and I want to do it.
The car is so big it's a bit absurd. You just can't take it seriously. However, it cruises down the highway like nothing else. I like having a little fun with my stuff and being just a wee bit different in my builds.
Anyone can build a cookie cutter car by following the same old thing everyone else has done. That's boring.