According to newcars.org the 4.8 has 295 hp. 14mpg city & 18 highway.
270 H.P. & 215 Lb/Ft of torque
The 4.6 Liter has 260 horsepower 302 lb/ft. I know nothing about a 1999 Ford 4.8 liter engine.
go to kelly blue book enter all your info and look for the page with the original specs. good luck caddyman94
5.3L 295 hp V8 Stock Horsepower (@rpm) 295 @ 5200 Torque (@rpm) 330 @ 4000 Displacement (cc) 5328 Bore X Stroke 3.78 X 3.62 Compression Ratio 9.5:1