I played with 65 Chevy truck this weekend I have a question

[Blk63vette]

Hello

I have been slowly working on my 1965 Chevy C10 truck. I managed to find a dipstick ( was missing when I bought truck I don’t know where it went) to put down into the engine today. I was happy to see black oil to full level on dipstick. I’m concerned about the black gritty stuff that was on bottom of dipstick. It’s not metal. This engine has not been touched since 1987. I would like to try and get it running again if possible. I was thinking the black gritty stuff could be deteriorating gasket or something?? What would you guys do before you started this engine?

Thanks

Pete