The Mark Engine uses actuators to open the long and short tubes at different RPM's doesn't it? This would be a nightmare to make happen without the Mark computer, I really doubt that it is possible to make it function properly if it does fit. For the time it would take you could problaby have the whole DOHC motor in.
Former owner of 94 Bird with DOHC 4.6L swapped from a mark VIII
2011 CTS-V Wagon
1968 Torino was an original 289, C4, fully documented numbers matching car. Now: DOHC 4.6L/T-56 swapped, Cobra intake, IMRC delete, BBK long tubes and H pipe. Dynotech Aluminum Driveshaft, 9" rear with TrueTrac and 4.11's.