I took the heads off my 52 F2 239 flatty and theres no ridge on cyl walls you can read the numbers on top of the piston and the valves you can see the word ford written on the valves no rust in water jackets the only problem I can see is some of my valves are stuck I can get them free but when they come up they wont go back down without assistance

 

maybe slightly bent .... i had one like that , got bent oh so slightly , while trying to unstick the motor . i was even gentle , which is odd for me . still bent it .

 

I guess they are avaible to buy somewhere if one is bent I hope I now believe this trucks mileage is actual 49k the inside of this engine looks better than some newer ones I have taken apart

 

What are the numbers on the top of the pistons? like 010, 020, 030, or Ford P/N's? AFAIK standard factory pistons have no markings at all, just the notch.

Varnish is also likely for the valve stems. if you can pop a valve up, dribble some lacquer thinner or acetone along the stem from the top (not a lot). If it's varnish they'll break it up quickly, but it will re-deposit, so ultimately you'll want to pull the valve assemblies out anyway for a proper cleaning. (Don't worry, it's easy)

 

Sometimes the valve stems get rust pitting etc and so they dont move to well, try spraying them for a few days with atf/acetone mix and move them back and forth until they move on there own. maybe that will help???
I got one to free up that way luckily without having to remove the head.

and another one that the head had to come off and even then it was not going to move easily

good luck with it.

 

ok had to go look the pistons have 747 written on them and they have 030 on them