So theres a pretty cool rust removal truck for smaller parts that you can do. All you need is some Sodium Carbionate. You can find this at swimming pool shops, or just buy some luandry soda or luandry booster because it has the stuff in it.

Get a plastic bucket or tote and fill it with water.

Mix the Sodium Carbinate in there, I heard its about 1/2 a cup for every 5 gallons. I just winged it.

Put the part needing cleaning in the tote submerged

Get a sheet of steel, the larger surface area the better and put it in the tote under water also.

Get a battery charger and hook NEGATIVE to the part that needs to be cleaned and POSITIVE to the scrap metal.

Turn it on and make sure the parts don't touch.

Let it sit for 12-24 hours. Right when you plugit in you'll see bubbles coming up from the part. It takes the rust off. Its electrollacis stuff, pretty cool.

I bought a 400ci small block chevy for the Jeep which was rusted together. We did the whole block and its not new by any means but it turned out a hell of alot better.

If you want more info just Google "Luangry Sode Rust" or "Rust Electrolicis" Something like that.