In states with emissions inspections, and even some without 'em, the law states you can only put a newer motor into an older car, and ONLY as long as you also transfer all of the OEM-spec smog equipment along with it. I'm pretty sure that even a half-wit inspection mechanic is going to know something is up when he sees anything newer than a 1989-model-year vehicle with a carbuerated ANYTHING under the hood. But in Iowa ... who knows. I dunno if they even have safety inspections up there. I know Kansas doesn't have diddly-squat, aside from a brief look-over if you bring a car in from out of state, just to make sure it isn't stolen or something, but it's otherwise a free-for-all there; Missouri, on the other hand, is apparently starting to get so anal that they're on the verge of imposing full-on smog sniffer inspections and crap there, so you might look at the long-term prospects of doing a swap like that in Iowa. (Good things never last forever.)