Nicks Garage 383 build

I just came home from dynoing my stock stroke 400. The specs are 8.5:1 compression, pocket ported 346 heads, Weiand dual plane intake, Summit 6400 cam (214/224 duration and 444/466 lift). I was trying to concentrate on low end torque to move a 4200 pound 1966 Charger with 2.94 gears. With the 650 DP dyno carb it made 420 lb/ft of torque at 3900, with over 400 lb/ft from 3000 to 4300. Horsepower was only 340 and it peaked early at around 4800 rpm. The torque was about as expected, and the horsepower a little disappointing, but given my stated goal, it should do the job.
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Headers used on the dyno?
Any idea what size?

Let’s see a sheet.

I realize for your combo, the cam requirement is going to call for something pretty small.

But I feel cams like that generally don’t produce power curves that look impressive on a dyno sheet.