Speedmaster heads are bare so I can do some of my own port work, select my own springs and valves. I take it some folks aren't fans of them, but I think for the price they'll work for me.
Since YOU can work on them, they can be a good head for you.
I would suggest a call to Howard’s cams and ask for a high lift HFT to work with your combination. I myself would yield at a duration of 236*’s @.050, have it ground on a 108 LSA, get as much lift as possible and that the head flows, if possible.
I stated 236*’s @.050, but a lot of this is in flux because of the love that is used can make a 236* ether very aggressive or Just OK. It’s a general area.