From what i've learned, you're not particularly looking to enlarge the ports, but rather you want them to flow as smoothly as possible. I've also heard that port-matching helps power and fuel economy and increases flow substancially as well. I guess my advice would be just to clean up any casting marks, smooth the ports a little and make sure that the ports line up.
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'84 Mustang 5.0 T5, FMS aluminum radiator & 180* thermostat, 1 5/8 shortys/2.5" duals, '88 GT tail lights and wheels, Holley 4160 4 BBL, smog pump idler, now with hi-po collapsed lifters in #3 or #4
