Willys F-Head 134ci Performance Upgrade info

[cj4a nz]

am having a look around but mine has started running rough(missing) and not reving
when I pulled the plugs no's 1&4 were black and dry 2&3 wet and black
has been running with the choke on a bit too much,but have fixed that issue am looking at hotter plugs??
ideas,suggestions???
the motor out of my daily looking temping at the moment eeeeeeeekkkk

[turbomart]

Id be checking compression, those old flat heads often blew the gasket between cylinders 2 & 3.

[cj4a nz]

turbomart I hope not only done a couple of hrs running after the head was off
gone to a hotter plug seems to be running better.................so far