Much more info would be needed. It could be as simple as a exhaust leak or as serious as a flat lobe on one of the cams.
1993 5.0 LX 'Vert
GT-40X303 heads, E-cam, 1.6 roller rockers,
Cobra intake, Edelbrock 65mm t/b, 73 mm C&L, CAI,
24 lb injectors, AFPR, 3.73's, March underdrives.
FRPP headers, Bassani catted X, SLP Loudmouth.
This thing is loud!!!
Pony R's with Eagle ZR's, stock AOD.
Cervini's Air Extractor hood
2003 GT seats
Springtime Edition mirrors & wing
ff member 157