I assume you're asking about the engine only, since you said "5.0". The LTD (Crown Victoria) engine had/has ES6E cylinder heads. It was rated at 150 HP.
If you're asking about the chassis, the '90 LTD CV was built on the "Panther" chassis, not the "Fox" chassis.
whqat about the grand marquis though? I noticed as the local junkyard that they had the 5.0 HO manifold, and the same general setup, but i didnt get to see the type of heads, because those were gone.
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Cardinal Red '88 GT 5 speed, Cobra Upper/Lower, Dynomax complete Super-Turbo cat-back system, Turbo Coupe Rear 10" discs, 3:73 gears, SN95 Master Cylinder, Summit Racing adjustable proportioning valve, Spec Stage II kevlar clutch, steeda adjustable cable/quadrant, 73mm front calipers, P.A. Performance 130 amp alternator, 99 Contour Electric Dual Fans, Battery relocated, rebuilt 91 T-5, Mass Air conversion
It may have had a manifold plate that said "5.0 Liter EFI" but nowhere on that plate should it have said "H.O.". The following were the only models that the H.O. 5.0L engine was available in.
Ford LTD LX - '84½-'85
Ford LTD 'Special Service' - '84½-'85
Ford Mustang - '82-'93
Ford Thunderbird - '91-'93
Lincoln Continental - '87-'90
Lincoln Mark VII LSC - '87-'92
Mercury Capri - '82-'86
Mercury Cougar - '91-'93
Mercury Marquis LTS (Canada only) - '84½-85
(I might be off a year or two on the Continental and Mark VII LSC.)
Is 90 Ford LTD 5.0 same was mustang 5.0 
