If its been ported already, you might not be able to run a stroker crank. Port timings could/would be off. If it was mine, i'd take the head off,measure the ports from the top of the deck (in MM),and then call one of the sponsors here.
I'd recommend leaving Jim @ Passion Racing a message and see what he can do with what you have. If it was ported by trinity,there might be some room left for improvements.