I am building something very similar to what you are talking about. I bought a truck with the drivetrain in it, and then made it fit in my FJ40. It is just getting ready to road-test, so I don't have any wheeling feedback yet. Vortec 350/SM465/NP203/Splitcase I stretched the hood 5" to push the motor forward to get the t-case back in the stock location. There are so many things that I had to do to make that work, and like others mentioned, it a lot of work to make fit in a full-bodied rig with a frame. I used the ruff-stuff rear 4-link and TMR 3-link kit in the front. I have a front Dana 60 from a 92 Dodge 1-ton, and a 14-bolt rear axle. I have 37s on it now, and 40s will fit.
With the rear coil-overs outside of the frame (for passenger room), there was a lot of work to make that fit, and even then, it just barely fits. I also wanted to keep the body with the hard-top to be able to go 4x4ing in sub-zero temps and drive it on the road once in a while.
I think your estimate is low, but I bought everything for mine in Canadian Pesos, so maybe that's where my gut feel comes from. There are a lot of knick-knacks that add up to a lot of $, AN fittings, hose, brake lines, fuel pump, fluids, wiring, driveshafts, etc. I would hate to add up what I have spent on this project.
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