cost to modify 2wd -> 4wd

More than it would cost to sell the one you have and buy a 94 with 4 wheel drive and a thousand times the effort ;>)

Unless you were planning on making a monster rock toy, it would be a waste. If you were to convert it to a rock toy, the IFS would have to be swapped with straight axle, the transfer case would need to be gone through for gearing. New drive shafts would be needed any ways.

If you are just wanting a truck with 4X4, then you would be money ahead to sell the 2X4, and buy a 4X4. You would have to do everything above, but for no real reason.

Plus, the labor involved. Generally if you are asking a question like this, you are not going to be the one doing the conversion. This will add quite a bit of $ to the whole price. It is not a bolt together project at all. There is a lot of grinding, cutting, and welding required.

more than any sane person would consider spending