If you've got the 76CC heads, you'll have 1.94" intake valves and 1.5" exhausts. Get a valve job done, and have the machine shop install stainless 1.6" exhausts and pocket-port the exhaust ports right under the valves. Have them angle-mill the heads .100" at the spark plug side of the head, tapering to zero at the intake side. This will reduce the combustion chamber volume to 60 CC, and give you a little more compression than those pricey 64CC double-hump heads. You'll also have the same casting number as the low-compression heads, in case a nosy tech inspector is lurking around. That's how I built 300+ HP "claimer" engines for the local round track. Swapping to a set of flat-topped Speed-Pro Hypereutectic cast pistons along with the head modifications will get you approximately 11:1 compression. Add a Comp Cams 268H High Energy cam and a good set of rams' horn exhaust manifolds and 2 1/2" exhaust pipes will get you around 350 HP, basically the same setup as the 300 HP 327's had, with the advantage of 25 more cubic inches to add a little power.
Jerry

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