I just bought a 1hp Delta 14" band saw. I got a 1/2" 4tpi blade for it and
have been playing with it.
It resaws 6" of mahogany easily enough, but bogs down on 6" of oak. I made
lumber out of black locust firewood, but it struggled.
It would be great to install a riser and be able to deal with larger pieces,
but since it doesn't do 6" all that well, I can't see doing bigger pieces.

I would appreciate some advice on this from someone experienced.
Will installing a riser block change it's performance on smaller pieces, or
will that be pretty much the same as it is now?

The black locust lumber is pretty neat; any reason it is not used?