I have a 1300 single port engine in my eagle ss. Not sure of mileage of engine.
I got it a long time ago to replace a truly knackered 1600. Its been sat about 6 years in the dry and i attempted to get it running with some new parts this summer. It ran poorly and i traced it down to low compression on cylinder 3. With heads off and valves out, I can see an exhaust valve was getting stuck causing back firing. All of the valve guides have excessive play.

I wanted to get peoples opinions on whether i should get new guides put in and maybe new seats. Or dump the heads for 1600 twinport.
My engine is code F and i think i would need to change quite alot to upgrade it to 1600 dp.
Im not really interested in power upgrades. I am aiming to get on the road as soon as possible.