340 sitting Question

[Confusedcuda]

Hello, a few months ago I bought a 71 340 from a fellow that was rebuilt and had about 5,000 miles on it since the rebuild. He said it had sit in his garage for a little over a year. When I got it, just to be safe, I took the J-heads off and had a valve job done cleaned them up, they checked out okay. I noticed in a couple of the cylinders, there was a line, like maybe rust, where the piston had sat at the very top. I have had a couple of people tell me to just hit the cylinders with some PB Blaster and when I fire it up, it would be off the cylinders before I new it, what do you guy's think. Should I be overly worried about this. Thanks

 

[66340SEDAN]

Can you rub it off while the heads are still off? Maybe turn the crank a little, then clean out each cylinder, then lube it a bit and let her rip. Doesn't sound like anything to worry about.

 

[340sFastback]

I'd spray some WD-40 on those areas and wipe them down with nice fresh clean cloths. A lot of that rust will come right off with WD-40. Then wipe the cylinders down with fresh motor oil up and if the engine spins around freely you should be good to go.