so I put a 4.8 in mine and ill just brake the cost down.
engine w/harness,pcm,fuse box etc $525
swap motor mount adaptors $35 ict billet
crank extender for converter $35ish ict billet
passkey delete from pcm $75, I also had a tune done and a segment swap for my 4l80e transmission since mines a 2500. so I had more in mine.
not needed but long tube headers $255
fuel line adaptors $65ish. mates vortec fuel lines to the ls rail. plug and play.
pretty sure that's it cost wise. stock vortec throttle cable works with out any modification. trim down heater hoses and they go right on the water pump, their even the right sizes! I modified my lower vortec rad hose. the upper hose from the donor truck will work. the ls fan fits inside the fan shroud. other than that its all wiring and getting the exhaust hooked up. I was going to use the manifolds and had about a foot in a half of the exhaust off the donor truck and was going to graft that and my exhaust together but the manifolds were warped so I bought pace setter long tubes for the 2000-2007.5 body style and used those. had to trim the inspection plate shield nub off the side of my trans and they fit fine. just barley touches the frame on the driver side. doesn't even rattle. just needs a SMALL dent. I ran a 12 volt b+ to the main power on the ls fuse block, a 12 volt key on to the a9 terminal on the c1 connector, used the trucks factory signal wire for the starter so my key turns the engine over, and ran a jumper to the fuse box from the fuel pump relay on the truck to the relay in the ls box to power the fuel pump up. truck runs. its that easy man. the speedo on the truck will work if you splice the vss wires from the truck into the vss wires from the ls harness. the oil pressure gauge will work if you splice the trucks oil pressure wires to the ls oil pressure wires, they use a sensor that's identical to the vortec 350 the thread pitch is just different. for the ect I used a 98 ls1 three wire sensor and pigtail and spliced that all together. you can run a wire off the ls pcm to make the tach work, I havnt done that yet. but the output signal will need changed for a correct reading. this is how I did it, there are cleaner ways. it was just easiest for me this way. lt1swap.com will be your best friend!!!