Deferens between -86 and 87- SBC

Hi. I got a 1987 305 for my rod but when I look in parts catalogue and web shops it seems like most thing does not fit on a 87 sbc and later. It’s clear why valve covers and oil pans are different but what about:
Water pumps
Pulleys
Brackets for alternators
Intake manifolds
etc.

Thanks
Thomas

Later use serpentine belts-early used "v"

Intake manifolds have 2 bolts that are oriented at different angle with respect to heads.

There are all kinds of alt brackets.

There are several different water pumps.

OK. Thanks

Thomas