If the engine is getting rebuilt anyway, put in pistons with a little better compression ratio. This is key to getting the engine up to its potential.
If the heads need a lot done to them (guides, valves, etc) then replace them with an aluminum "replacement" head like the E-street head or the Stealth. Much cheaper in the long run to buy these then rebuild 40 year-old cast iron heads. You'll also benefit from lighter weight and a little better flow.
'63 Dodge 330
11.19 @ 121 mph
Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs.
10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.
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