1995 K2500 LQ4 swap

[95chev-w/t-guy]

OK, so I have this rusty old 1995 GMC K2500, the engine is toast (headgaskets and overheated a few times, and sounds like it's knocking). I was going to sell it for parts at first, but I just got an amazing deal on a southern box that has me rethinking what I want to do with it. Here's the thing, I have an LQ4/NV4500 from a 2wd 2001 2500HD sitting in my garage. I already have other plans for the NV4500, but that leaves me with the LQ4. Immediately after I found this southern box it dawned on me "put the LQ4 in the K2500". I've never done an LS swap before, but I've been toying with the idea and doing some reading and it doesn't seem that bad. 96-98 fuel pump, corvette regulator/filter, reworked stock or painless harness, engine mounts, etc. My 95 doesn't have cruise control or A/C, and I don't need it. I'm assuming the 4L80E in my 95 will already work with the LQ4. My first question is, the flex plate and torque converter, will I need parts from a newer truck, will the parts from the 95 work, a combination of both, aftermarket, or is it all the same? Considering I have most of the major parts required in my garage already and have basically nothing into this so far, I don't mind spending a little on doing things correctly, so long as I won't need a 2nd mortgage to pay for it Here's the truck.

P.S. the engine is complete with accessories and I drove the truck it came from. I also have the original harness up to the firewall, the computer, factory fuel lines back about 3 feet, etc.