The airflow for that engine, even in OEM trim is compromised.
Professional cylinder head work(not some "street port" stuff)along with the proper cam selection, for your riding style will be by far, the most cost effective route.
Naturally we would like to see the bore increased to 3.934", (107") as the larger valve reliefs are in place, to accomodate the 1.940" intake valve we would use in our Stage III Sport-Touring Head, but the OE 103" pistons can be modified in a piston vise/vertical milling machine.

Scott
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