1999 Crew cab OBS 5.3 Swap

[Rogerfe]

Hey guys,

I've been doing as much reading of this forum as possible in between school and a full time job, i just have a few questions that I couldnt find answers for, I would really appreciate any help with the subject,

I recently purchased a 1999 Chevy 2500 Crew cab with a 5.7 and the 4L80 transmission, the 5.7 is now toast and I would like to swap in the 5.3, my questions are,

What flex plate to use? I see that from a faq people are saying
"This means, you must replace the factory 5.3L flex plate with a flex plate and spacer from any 2002+ ¾ HD GM truck that originally came with a 4L80e transmission."
Is this true for all variants of the 5.3?
Will the stock converter from my 4L80 bolt to this?

Thanks guys