Feel like my 440 should be faster

'Sick of throwing money at it'.

Probably the least expensive 'fix' is a cam change. You have UNPORTED factory heads. These will limit upper end hp. No point using a 6500 rpm cam with 5500 rpm heads. It just leads to tears.....
I would try & find a 220-225 @ 050 cam, 108 LSA, single pattern.
Might be tough to find in a roller cam.

A back up would be a FT cam such as the Isky 270 Mega. Find some factory lifters, have them re-faced & good to go. You can also use SB lifters, maybe easier to find...