E3 means 83, thats the first year of the turbo EFi in the thunderbirds. does it have a cap covering the mechanica fuel pump hole or is it casted part of the block? the blocks are 99% the same with very little changes throughout, the thing that really makes it a SVO is the ECM. use this website and punch in the catch code off the ecu. The TwEECer -- Ford EEC user programmable module