[Nick_R_23]

In your case, buying a complete donor truck and using everything possible from the LS donor would probably be the ticket. You can find wrecked ones for anywhere from $500 to $2000. Part the truck out and sell any body, interior, or drivetrain parts to make some money back. Buy a pre-wired Swap Harness and Dirty Dingo slider mounts, and if you do research, you can usually find a set of OEM manifolds or low buck headers that'll fit just fine. Use everything you can and try not to get bit by the upgrade bug, and you can get away fairly inexpensively.

Just for an example:

Typical donor truck cost: $1500 (Reuse as much as possible)
Dirty Dingo engine mounts: $200
Typical standalone swap harness: $500
eBay LS headers: $300 (Gen 5 Camaro manifolds usually work in most swaps and can be had for about $150 used)
Aftermarket fuel pump and lines: $300
Subtract any parts you sell from your donor truck: -$???

So right there, we have an engine, mounted in the truck with exhaust, fuel, and it's running on the factory PCM using stock truck accessories and intake for $2800, and that's before selling off any donor parts. The thing that gets most people is the need to swap parts out for "something better". The moment you change intakes, change accessory drives, or make any kind of mods, the swap costs jump significantly.

For my '67 Camaro, I picked up a 2007 Chevy 2wd dually box van off Craigslist, wrecked with 41,000 miles, for $1650. It had a 6.0L LQ4 and 4L80e transmission. I sold the complete van chassis for $900, which left me at $750 cost so far. Then I sold the stock 317 heads off the engine for $300, and traded a few other pieces for a set of 243 heads. So I ended up with a 6.0L with 10:1 compression and 4L80e transmission, both with 41K, for a mere $450. I still have more to sell off the van that I won't use, so it'll probably be even less. The deals are certainly out there if you look for them.