Put a set of Chevy 307 V-8 pistons in it and shave the head .050". That will give you about a 9:1 compression ratio. Then get McGurk or someone similar to grind a cam with about a 260 to 270 degree duration. If you can find one of the intake manifolds for the big rig 292's that ran the 2GC Rochester carburetor, that will give you enough volume to take advantage of the increased compression and cam. Maybe add a split manifold or a set of cast iron headers and steelpacks to free up the exhaust. You'll spend enough to buy a V-8 crate engine, but it's fun to outrun a V-8, and then open the hood and show off the 6-banger!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!