Also, take a look under the hood. Take a close look at the fenders where they bolt to the engine compartment frame. If you see some crumpled up areas with rust, you can pretty much bet it's been hit. Also, any collision will usually chip the paint off on those edges.
Another area to look at is the radiator supports. If it's been wrecked bad enough, they likley had to be replaced. Since it takes a fat daddy spot welder to weld them like factory, most places drill a hole through the frame and support and weld around the hole.
Other than that, it should idle smoothly at around 700 rpms, give or take 100.
Vibrations and highway speeds can be a pain in the rear. Sometimes it could be worn tires in need of balance, or it could be engine mounts, driveshaft, flywheel, etc....pain in the rear to track down. Keep that in mind.
Happy hunting.
--nathan
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--silver_pilate
'91 GT, Built 306, Wolverine 1087 cam, ported Windsor Jr. Irons, and all the goodies...click the link to the left to see a full list of my mods...
Tried and True 302 Being Built to Outrun You! heh heh heh...
--Texas Panhandle--
Check out my site