I just bought a 53 olds with the 303 rocket I did a complete tune up but I have a lifter tick I can’t seem to get rid of any help would be appreciated thanks
'49 - '56 Olds were famous for noise in the valve train when the mileage got high, when the oil didn't get changed, or just old age ... Back in the days of cheap oil, we used to do 2 or 3 quick oil changes with a pint of ATF thrown it. Sometimes it helped, usually it caused more problems that it fixed. Bottom line is live with it, or be ready to spend a buncha money.
Pull the valve covers off and see how much oil is reaching the rocker arms. Oil comes up the center rocker stand and feeds the shaft. Would not be surprised to see the shafts packed with sludge. You can remove the end plugs and clean them or replace the shafts if necessary. At least then you will have better flow of oil to the shafts/rockers. Might help as might the oil additives.
Agree on pulling the valve covers for a look see. Avoid the temptation to pick away at the sludge if you have a significant build up of it. It will get into the oil pan and be picked up by the oil pump. I have had good luck with adding a pint of MMO (Marvel Mystery Oil) in with the oil and drive it around for a few days, dump the oil and install a new filter.
Back in the day Whenever an Olds 8 drove in you could hear it from thirty feet away. Even with your back turned, you would know what ( or who ) was approaching. The owners were not negligent. It was just part of the Olds character.
My dad had a 53 88 when I was a kid. And yes they all did it, bad non detergent oil, and too few changes. I would pull the rocker covers and the oil pan, clean out all of the sludge before I started putting stuff in the oil. If the sludge is an inch thick in the pan you don't want to get it loose and have the oil pump pick it up. Then after cleaning out the rockers and pan put 1 qt of ATF in with the oil and run it and then change again. Do that a few times and it may clean out the lifters and stop the clatter, if nothing is worn like a rocker or shaft.
Before I put it in my car, I tore my 303 down, cleaned all the sludge, cleaned out the oil p***ages to the rockers, got it **** and span clean and the lifters still ticked.
Not speaking about Olds but valve noise in general.... Something overlooked when chasing a valve tap, can be an out of round lifter bore.