Are 3rd gen injectors better???

those are called ev6 injectors, 86-93 used ev1, the spray pattern is different ( 4 hole vs single) there are 2 different electrical connectors called uscar & jetronic for these inj. just make sure u get the right one, i just bought 24# inj ford racing part# m-9593-aa302, these will have the right elec connection ( jetronic) to be used with the 86-93 mustang

The fat injectors from the '91 have a single pintle; the one you have in the pic is from the Explorers and newer Fords (EV1) and they have Four pintles, so they atomize the fuel better. I'm using the Explorer style and they're 19# just like the Mustang, so if you have all eight go ahead and use them, they plug right in without modification.

The newer EV6 injectors look almost identical to the skinny EV1 injectors except they have a more rounded elec. connector, and they dont fit without adapters for the connectors.