The James FIRE RING head gaskets (not the bog standard James ones) are also excellent.
I think you are dealing with a Shovel here? Owing to the geometry (angle of the pushrod etc) , the front exhaust always shouts first. Probably rocker arm needs shimming....
http://www.celticthunder.net/RockerBoxBuild.htm
NOTE: like he says in that link, if you are sold the Ramjett rocker-box kit with shims in a packet and it has black wavy washers.....ones that look like some toddler has bent them...DO NOT USE THEM. They will break up in your engine. They are a confirmed danger to Shovelhead engines.