Chris, please check this out as this info is slightly off...from the intro page.
Codes for other models of 401's is "LS" (edit-LT = 401 ) as used in Riviera, Wildcat and Electra. There is also the "LT"( edit.. LW would be 425 single, LX = 425 dual quad) code 425 with two four barrel setup. Used in the Wildcat, Electra and the Riviera GS.
Thanks Chris, just getting particular. I've spent a little time researching the 65 Wildcats, they designated the engine options
L90 A5 Export low compression 401 single 4bbl
L75 A7 Wildcat 465 single 4bbl 425
L80 A8 Super Wildcat dual quad 425
Cheers, Ted