Using the sample paint on the flywheel is your most accurate match to '66 327 green, other parts of the engine has been exposed to high heat, weathering and bleaching out( due to engine degreasers etc). IMO, Ford green is the closest match for the 292 and 327 in a ready to use rattle can. But if found someone who can match color with high temp paint,great, go for it. Member Sodly has a super low mileage 327, which appears to be closer to Ford Green than the lighter Alpine Green ( aka Detroit Diesel Green).
http://www.ebay.com/itm/VHT-Paint-Hi...693832&vxp=mtr