Ported X head 340 header size?

Then I’ll assume this is a bit of a beasty or an engine.
What’s your cam duration @050?

Maybe milder than you are thinking? ... duration at .050" is 235/243, it pulls pretty good 2200 up. Solid with EDM lifters. Fun cam with good pull and a nice sound. I'm only running a 2500 stall from PTC. I do wish I would have had the heads flow tested the last time I had them off.
Just a feeling, but I think the motor would like to breathe better. I have yet to open the intake for the TQ (adapter for now) and think the headers are too small for what it wants. No way to know without trying it.