I pulled the heads off my 305 which i had planned to do a head/cam swap on but the pistons are disgusting...ALOT of carbon..so i decided to go ahead and put a brand new 350 in its place. It may not be dead but how much carbon is to much? The valves are pretty nasty to i pulled them out of the head. All the carbon would explain my wierd compression test results

 

alot....?

Hard to tell unless i was looking at it. It's completly normal for the entire piston to be covered in carbon though.

 

the pistons are completely covered plus there is buildup around the edges...you run your fingers around the piston and you come up with flakes on your fingers...i dont know maybe its a normal amount but Im pulling the motor anyways because the compression readings were off pretty good....and because im 4 tranny bolts away from being able to pull the motor anyways.