You haven't even got the donor engine out yet and already L31 express has you thinking you need a cam for it or its useless.
I'm not sure why he has a one track mind hate for LS engines. Maybe another guy in a Van with an LS at the track spanked him in a race? But I have to wonder,,, could there really be 2 vans on any race track at one given time? Do people even race vans? Is that a thing? So many questions
Nobody I know has been unhappy after swapping their sbc for an LS. One thing to remember is that 5.3 is way more capable than a 350, and even a 383. If your planning on hopping it up, it will make more power per bolt on than any sbc would