The first *relay* you posted is the later style and is what came stock on trucks with EEC-IV. That includes vehicles with feedback carburetors and EFI. This is what originally came on my own truck.
The second one you posted is the earlier style that Ford used for about thirty years. These came stock on vehicles with conventional carburetors. I switched to this one when I did my DSII conversion only because that is what I saw on all the earlier trucks.
Having said that, I would *think* that the later style (first picture) has something different for vehicles with engine computers. But I don't know for sure.
Steve83 says the later style is superior to the older style, but I haven't had any issues with mine. I think the main thing is to try to get an older MOTORCRAFT one. I will say that holding each of these - both of them being MOTORCRAFT units - the earlier style relay feels quite a bit heavier than the later style.
Lucille: 1985 Ford F150 XLT Lariat
*Colors: Dark Canyon Red exterior, Canyon Red interior
*Engine: 5.0, CompCams 31-230-3, "Thumper" E7 heads, Edelbrock Performer intake, Autolite 4100 carburetor, DuraSpark II ignition, Thorley Tri-Y headers, Flowmaster dual exhaust, H-pipe.
*Drivetrain: AOD transmission, 3.55 gears, 2wd.