My cars liked the extra initial timing of the 2x4 spec distributor.... it helped off-the-line performance.
The 2x4 dist uses 10 degrees initial advance vs 2 deg of the std dist. Both have the same max advance of 30 deg.
I put lighter advance springs it as well, full advance by 3000 rpm vs 3900 rpm stock.
As far as the heat crossovers, Doc liked to keep them, he felt the heat helped atomize the fuel and improved drivability.
I install plugs in the manifold in the channel just under the carb. It still warms the intake, but carb is cooler.
Different intake gaskets will keep intake cooler.
Tough to definitely say what works best, how you're using the car (and the weather) influences your choice.
