my 300ex cam was 180 out, i fixed it, however when i crank on it it backfires, like the timing is retarded, i know you are supposed to align the notches with the head, but it is impossible, it is always too far forward or too far back, help me, suggestions are welcome

 

your timing chain is probably stretched. try getting a new one. thats what ima have to do with mine.

 

check tension on cam tensioner if its loose it will through out of time

 

the chain is wore out