06-04-2019, 05:34 AM
(This post was last modified: 06-04-2019, 06:26 AM by centerfire.)
The gas block rear set screw is centered under the gas port. Spin the gas block over so the set screw hole is over the port and check the distance from the gas block journal shoulder to the end of the gas block. Replicate that distance with the gas block oriented in the correct position.
Eta: I missed the OP has a clamp on block. You can still measure the port distance from the edge of the block.
Eta: I missed the OP has a clamp on block. You can still measure the port distance from the edge of the block.