Your car is awesome !! Will be running my 94 when the weather breaks up here. I am told that the motors in the 94/96 Fleetwoods are not exactly LT1's, that they either had different heads or cams, or both, is this true? Also what rear end is in the Fleetwood, can a posi unit and gears be purchased aftermarket to get a 3:73 combo like yours, or did you get an Impala SS rear ? Thankyou for any light you can shed on these questions.

The Fleetwood LT1 is the exact same motor as the Roadmaster sedan/wagon, Caprice wagon, optional Caprice sedan, Impala SS motor from 94-6.

The cam is made for torque, so the profile is different from a Camaro/Corvette LT1 cam which has a little high end spunk to it.

Also, the heads on a FW/RM/Impala/Caprice motor are cast iron with pressed-in rocker arm studs. Corvette and Camaro (Firebird) have aluminum heads with screw-in rocker arm studs.
Head gaskets used are slightly different. Iron heads typically flow a tad better than 95-and earlier alum heads, but the weight savings iron vs. alum usually negate the flow benefit. This area is a cause for heated discussion, however. :slam

Caddy Fleetwoods got a complete different rear end than B-bodies (Impala, Caprice, wagon, etc.).
Main difference is the 4-channel ABS. B-bodies got the 3-channel ABS with a reluctor in the rear end housing, but the D-body FW has a ABS sensor at each wheel. Still a 8.5" housing, so Impala posi diff. and gears will fit like a charm. I had 3.42s and an Impala stock pois unit put in my Fleetwood's rear end.
Other difference is the drum brakes on the Fleetwood. The Caprice 9C1 and Impala SS have rear disc brakes.