It depends on what the previous owner used off the factory turbo engine and what he used off of the 93 engine. The pistons, head, injectors, ECU, radiator, Air Flow Meter, and exhaust manifold are all specific to the turbo motor. But the previous owner should have reused all of those parts. I am curious as to how he plumbed the oil return line, since the normal 22REs don't have this provision in the block. <img src="/forums/images/graemlins/confused.gif" alt="" />

The naturally aspirated motor will have higher compression, but that is not necessarily a problem if you keep the boost low because the factory compression on the turbo motors was REALLY low. What is puzzling is that it ran good for a week but now there are problems. Can you describe the issues you are having? Stutter at idle? Smoke? Won't rev?

Jeff Moskovitz is the resident turbo guru, he highlighted some of the issues with this motor recently in this thread . How many miles are on your truck? It is possible that the original issue the previous owner was having was related to the turbo and not the actual engine and he replaced the wrong part. That would explain why there is still a problem but not why it ran good last week.