Hi all, I have an 83 firebird with 5l crossfire, brought car with engine already out and partially dismantled, was told that the engine was taken out due to needing work done on it, ie new timing chain, brought new timing chain set and went to put it on and noticed that the old cogs are one tooth retarded, as i am unable to contact previous owner I decided to put new cogs on and rotate engine manually a few times to make sure that no interference, all rotates good, in amongst the parts is a timing marker that screws into the timing cover, i am worried that there may be a different than stock cam in the engine and as soon as I attempt to start her up she will mess up the valves, is this possible?, is there any marks on the cam to look for or have I got to value the cam to valve ratio first, never been this deep into cam and engine timing before, many thanks and best wishes

 

Anything is possible when you take over someone else's engine project. As far as marks on the cam goes, AFAIK, no small-block factory cam was marked on the sprocket mounting surface; aftermarket cams may have ID stamped into them or not.

For now, all you need be concerned about are the timing marks on the engine and cam sprockets.

Install your new timing set with the timing marks at their factory position, and replace the front cover, balancer, and your bolt-on timing marker. Turn the engine over by hand to #1TDC and look to see if the mark on the balancer lines up at '0.' If it does, you're good to go; if not, either find the correct marker or else remark your balancer to correspond to your timing tab.


If you have any doubt as to whether or not there's adequate piston-to-valve clearance, your best course of action would be to pull a head and actually measure it.

 

Thanks for your reply, I had already set up like you have suggested but I just wanted to make sure that it was good, thank you very much for putting my mind at ease, best wishes