Planning for 408 - Possible Solid Flat Tappet cams

A custom cam will also get you what you want.
Picking from a catalog by "smallest to biggest" only guarantees you'll wonder "what if" for years to come.
Talk to an expert and they'll steer you into what fits your goals with more accuracy.

I have a similar combo. Full weight stock dart with a 408, 4 spd, 3.91s and TFS heads. I'm running a hydraulic cam though, 251/257 @.050 (295/307 adv) on a 110 with 1.6 rockers for about .590 measured lift.
It's strong, it will fry the tires from a roll in 1st through 3rd from 2k rpm, but I should have gone custom. I've got other changes to make first and then I probably will next year.

The split duration and wide lsa are doing me no favors. The TFS heads are good, but still too small for 400+ cubes and so trying to squeeze revs with the split and wider lsa is just dumb because the flow isn't there, I still only idle with 8" of vac and it stops pulling (butt dyno) just over 6k.

If I'd talked to an expert, I wouldn't have had to figure this out by reading this forum trying to understand my new engine's behavior... So save yourself the grief and go custom.