So my father-in-law and I picked up an 87 LX 5.0 that was T-5 swapped recently. When. He first went to look at it, it ran fine. When we went to pick it un it would not start. We put it on a dolly and brought it home with the plan that we are swapping the T-5 into his 89' GT vert and his AOD into what will be my 87'. Today we adjusted the timing slightly without a timing light and we got it to idle well. The alternator is good, the battery is good, it's obviously getting fuel to idle.... However, as soon as we slip it into gear and try to drive it stalls. We are at a loss as to what is going I or what to check next? We plan on getting a timing light, to dial it into to stock timing perfectly. It just seems baffling that it runs in neutral but not in gear??? Any ideas or help would be appreciated!! Edit: Does this sound like an IAC issue?