these cylinders can be use with both a 4 mill crank or a stock 350 crank. With a 4 mill crank will be a duneport cylinders with exhaust at 196° and transer at 126° . If choose to use with a stock stroke crank the exhaust would be just at 200° OR 199° depend on the.cylinder gasket you choose to use and tranfers would be at 122 ° you could go up q little on the tranfers to make.them a dragport for 350. This are a good pair of running cylinders very clean portjob done by a local builder. they were recently bored to 65.50 but one proclain.of a sparke plug broke loose and made a scracht on top of the.exhaust can be use as they are I was using them like that these cylinders ran like a rap ape asking $180 SHIPPED
text for pictures can seem to get them to upload through my phone new at selling through here