cause4panic

As the title states, I am looking to build an LSX block for boost. It will be going into a 1984 regal with plenty of street use. I have very little knowledge on the LS series of engines, I am stepping up from that LT1 turbo caprice that’s in my sig and need all the help I can get.
Summit has two different part numbers listed

19166454
19166097

Main differences that I see are
225lbs vs 250 lbs
Nodular iron vs steel billet
One is listed with “OEM” mains the other with “LS” mains
And finally the 9.26” vs 9.70” deck height
Some questions
1) Should I attempt to use someone local for machine work or should I use someone like LME, Katech, TSP etc etc
2) Displacement, will the engine be that much happier keeping the stroke below 4.1-4.0?
3) Standard or tall deck?
4) What the hell is this LS2 conversion that I read about?

Thanks
BB

Injuneer

We have 2 forums where this question fits better - LS1 Based Engine Tech, or Forced Induction. It isn't "Advanced Tech".