newer motor switch difficulty?

[Captkaos]

Street and Performance has: (this is a PDF file) LT1 in a '83 pickup
http://www.hotrodlane.cc/PDFFILES/83chevyLT1install.pdf

S&P LS1 in a '77 pickup:
http://www.hotrodlane.cc/77chevytruck/77chevy.htm

I am working on putting a TPI in my '78 Jimmy. I recommend an intank. All you need is a sending unit from a '87 pickup and use a AC Delco EP 241 pump instead of the TBI pump and you need high pressure hose to replace the rubber.

I am not to savy on CA smog, but from what I understand it will be required to meet emissions based on the motor year if you swap it instead of the truck year. Maybe someone more in the know will drop in to answer.