It depends on what parts you are using. I easily had $5k in parts alone. But I bought parts that were available as a bolt on / direct fit application (no fab work)
Engine / Tranny combo - $2000
BP Automotive - Stand Alone Harness with fan and fuse kit. - $700
Entropy LSX swap radiator, fans, specifically built for the truck. - $900
EFI Fuel tank, system, pump, lines. $500. Since you have a truck it will be more since you will most likely need to have something like a boyds EFI tank.
Dakota Digital gauges - plug directly into the OBD2 port and read off the computer instead of wiring every gauge. $1000.00
Motor / tranny / t-case mount from Advanced Adapters - $800 (2wd trucks are way cheaper)
Doug Thorley Headers - $700. You can find TBSS or camaro manifolds for $100 or less.
Full Exhaust system / mufflers - $700
thats not counting any suspension, brakes, wheels / tires, I have no AC, if I had a truck then I'd want it. $1500 there.
No idea what rear end you have, if it has posi? wrong gearing for the 4 speed auto? etc.
Not trying to scare you, but what i usually end up with is the budget number that I think it would take to build it and then multiply by 1.5.
That being said, lots of guys do this cheaper with different parts. I just wanted to give you my view from 30,000 ft.
Secondly, someone said to sell your truck....I love those trucks, I'd be interested if you want rid of it.