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Old 11-09-2012, 08:15 PM
69 widetrack 69 widetrack is offline
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If I'm correct the #99 heads are 1971 vintage yielding 265 HP in a 400, The 6X heads have bigger valves 2.17 intake, 1.66 exhaust, but lower compression. Milling the heads will increase compression some but to get to where you want to be might be tough. Have you looked at finding an older set of heads, or maybe a set of 4X with a smaller combustion chamber to increase compression?
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