Two things.
A Ford Modular motor is a versatile package that has proven dependable and has plenty of performance potential.
It is a wide package and so doesn't make sense in some applications such as GWs 33.
Ford started putting EFI on the 5.0 in 1980. They refined this motor until 96 or 97 when they switched to the mod motor in the Mustang. You can build a Windsor with all kinds of potential and streetability using either Ford or aftermarket parts.
Fords little 5.0 reignited the pony car wars and reintroduced hp with EFI and emissions standards.
But if you want more that 500hp from a factory crate motor Ford Windsors are not for you. You can build one easy enough but you need to hook up with a good builder.
Chevy kept at the pushrod v8 and so was born the LS. They have kept refining it to the level it is today. So from the factory you can buy a well mannered high hp OEM engine for a decent price. And this engine shares the same basic dimensions as SBX from the 50s. So you get equal modern refinement to the Mod motor in a plug and play for old car size, can't deny it.
They run well and don't leak so I agree with greg hood down for a car you drive a lot they are a good package. But open the hood and they look like crap. They also never sound as good as say an SB2 or a SBF.
So pick your poison.
GW just likes LS motors and for good reason. But an EFI Windsor could have delivered everything he wanted. It's not like an LS is the only option although it is probably the easy way out if you don't care what is under the hood.