I have a 4x4 1972 suburvan with a 350 engine. What do I need to do to convert it into a 4x2?

The easiest way is to just disconnect the front drive shaft., But if you dont want all the extra weight up front, you will need to remove it all, remove the transfer case and tranny. Get a rear drive (regular) TH350/TH400 tranny, you might also need a new drive shaft (tranny to rear diff). Then you will need to replace the front suspension, brakes, steering (that is if you want to go to a true 4x2). There is a ton of parts to come off and a whole lot of new parts to go on. If you just remove all the front drive stuff, you will notice that the ride is BAD (all the extra weight will lighten up the springs) LMC Trucks have free catalogs you can order, in it there are some pics that show the two different systems. This is NOT a weekend job, there is a lot of work to do, as I am sure you have already guessed that. When I was in school my teacher had a friend who switched his 74 GMC K20 4x4 into a C20 rear drive, well it took us almost a full year (3-5 hours a day) to do. If there is a shop in your area that you trust, they might be able to do it quicker, but there is going to be some heavy expeance. Best of luck and hope this helps.

take off the front drive shaft thats all but its costy if u dont know how to do it yourself