Spartan lifter tick
 

So my 96 ranger needed a new engine. we purchased a long block from Spartan through Advance. This is the third replacment engine and it has started to tick. It is lifters. The second had a bad leak down test and low oil pressure, i want to say around 27, they say anythingover 40 is acceptable. We have gone through the proper prime and break in procedures and have literally replaced EVERYTHING under the hood from radiator to power steering gearbox and pump, everything that attaches to the long block except the injectors which were fine on a bench test (twice) and the computer which has no issues as per snap-on. If not spartan being completely incapable of remanufacturing a 2.3, What could possibly be making these engines burn through lifters and tick within the first two weeks? 8 plug 2.3 liter manual trans. All three motors have had lifter shims. Please, all reasonable opinions will be considered