1964 Valiant "Get Runnin & Drivin"

I don't know of a high flow mechanical fuel pump for a slant 6, do you? I "guess" I could get a big block hv pump and swap the arms out since other then that, they'll interchange. I don't thing it's running out of fuel though. It would lay down on hard acceleration draining the float bowls and it's not doing that. At all.
And your plugs would show it.