Best M8080 NOS tube for CJ preamp line stage?

Have tried different valves in my cj classic pre se.Have found the mullard m8080/cv4058 nos valves to be the best.Upgraded my classic to se.This was a excellent mod,well worth the money.Have had issues with left channel tube rush getting noisy.Have you had any problem's.

no problems really; just waited too long to replace the m8080's and did it with stock dealer tubes. The difference in sound sparked a new level of understanding re. the potential sonic impact of tube rolling. I know I can do better so will give the mullards a shot. do you have a year recommendation?

Nos mullards are hard to find.Conrad Johnson have replacments.I was lucky enough to find 20 sets 1972 at a very good price.