From the looks of it the engine looks like a '93 - '98 Lincoln Mark VIII Mod Motor (all-aluminum 4.6 L DOHC 32-valve V8). It looks to have the coil on plug design of the '97 - '98. It was rated at 290 HP but in a Pantera it got significantly more.
Wilkinson did a number of conversions with that Motor but switched to the Cobra version (rated at 305) when they came out. He used a MOTEC ignition. He probably did this one although some others were doing them too. Steve helped me with my 4.6 conversion with parts and moral support. I broke with his approach by adapting the Ford EEC V to the Pantera. Steve claimed ~360 HP for the MK VIII version. Depending on what you think the engine to street dyno correction factor is (20 to 25%) that equates to 270 to 288 RWHP. Zonkey's RWHP is about 289 (last tested) with the '99 Cobra Mod Motor that was supposed to be 315 HP (but there was a lot of controversy about that and a big recall program of the Cobras).
King, I assume you decided not to put any details about the engine in the add. Just wondering why. I'd think it should add more value than not and advertising it as 4.6L for those who don't know, would be a downer.