When you say almost have you tried installing all of them and adding oil and then prime the motor? If not try that and also rotate the motor over two or more ecomplete revolutions, if the oil pressure doesn't drop while rotating it over and it has 60+lbs or more your good to go. If it drops and recovers while rotating you need to fix it. There are several different brands of lifters that have the skirt around the rollere wheel extended on the oil galley side, which will fix that problem. Contact Brain, OU812 and ask him if his will do that also