How much would it cost to make a 2wd drive f150 into 4wd?

So i own a 1985 ford f150 stepside and i freakin love this thing its my first truck bought it myself and frankly the stepside is just sexy. But she's a piece of work! Which is fine. But i was wondering if anyone on here could throw me a price range on making it 4wd, i already need to replace transmission shocks and the rear axel and brakes so yeah! I know its possible and difficult and that a new truck would be more wise but i just wanna know a price range! Any help?

I was thinking about doing this to my ranger except doing a Solid Axle Swap when I had it. I sat down did all the research and crunched the numbers. I figured by the time I had bought and done everything I needed to do I would be better off just saving my money for a nicer truck. So what you really have to ask yourself is
1) is your truck worth the time and money.
2) Do you have the time and money
3) Do you have the tools and the know how
When all is said and done it could be anywhere from 5k-10k. If you do the doner route it will be close to the 5k side but you still have to buy misc wear parts.

The cheapest way would be to look for a used 4x4 of that year and swap out the running gear into your truck. It would be a load of work but that way you get all the parts it would need such as matching axles, driveshafts, transmission and transfer case, etc. If the donor truck is the same year and the frame is straight it might be easier to swap your engine, cab and bed onto it.

On some trucks even the frames are different between the two. So, unless this specific truck is very special to you, cheaper to sell the 2wd & buy a working 4x4.

It would cost much lees to find and buy an '85 4x4 and fix it up.
You would need trans, transfer case, both driveshafts, front and rear axles (differential gearing must match), front axle arms, front hubs… And more.

Body parts from your existing 2wd would still match.

Buy the other vehicle for parts and start tradin.
How much can you find one for?

At least a bunch and a half.

At least 7,800 $

More that your truck costs. If you want a 4X4 truck you should buy one that is.

If you are equipped to do all the work yourself it would merely be the cost of a donor FWD. The rest is your time.