Advice Needed - Can't Start Rebuilt 273

loosen the valves up too i would do that first your hanging the valves open and its not going to pop if you were at 135 even but 90 your not closing it couldnt pop if it was timed right aar tony showed me that first when i was tryin to set my crane gold rockers
that was over the phone i had it real close just with his instuction enough to find my timing chain was worn out stretched after years of abuse like he said lube the **** outa every thing and dont turn backward to find tdc go around again i got done hit the key it fired right up i buttond it down and i could turn backward 1/4 to 3/8 thats alot of slopin the chain like some 1 suggested get those valves closed first turn by hand dont go bang make sure pluggs are out