Sounds a bit like Jasper Engines
Please, did you have to ruin my day by bringing up that name!
Once we did an R & R of a "defect" engine, requested of us to do by them, and were assured a "replacement engine would be delivered, and all costs would be covered by them under their warranty program"; but it was probably something like eight or more months after the vehicle had left, and probably a dozen phone calls on our part, and we still hadn't been paid!
Another instance, a customer came into our shop to buy spark plugs for his S.B.F. powered car; he had two sets of four on the counter, but they were different numbers? I said to him: "by the way, you have one set of 14mm and the other is the 18mm, are you sure that that is what you want"? He says: "yeah, my "new" ("rebuilt") engine in his car used 14's on one side and 18's on the other!
Must have been one of the earlier examples of a 'variable compression engine'!
And in another, a customer came by with his warranty-replacement "rebuilt" engine, to replace the "defective" example he had; and since this was the third replacement and he was getting tired of swapping engines including the costs not covered under the warrenty, he was asking if we could perhaps "check-it-out" before he went to all the work to swap-it-in? Same story, two different cylinder heads (yep, 14's on one side and 18's on the other!) but when we did a leak-down test, and I realize that a new engine, sitting on a trailer, just picked-up from the auto parts store, might not provide the most accurate testing format, but when one side exhibits a 60+% leak-down rate!
And yeah, Jasper is still in business!
Scott.