I have the heads off and I am planning on putting the heads back on this weekend. The top of the pistons seem to have a build up of carbon. What can I use or do to remove it? It's not like a quater inch of build up but there are some thick areas.
Thanks!

 

My friend used (i think it was) o'reilly brake cleaner to clean off his valves and heads on his 498ci bbc

 

i used brake cleaner with a rag and just scrubbed away.
jesse

 

I've used a razorblade in the past. Just make sure you scrape towards the center of the piston, then take a vacuum and suck up the gunk. After that, you can use brake cleaner or anything similar on a rag and rub the rest off.