looking into doing a 01 F-250 6.8L V10 swap to a cummins. Which engine should i swap to 12V or 24V? i would love to hear a few tips about how to do things as i am going to do it myself. Anybody who has done this is there anything you would do different and is there any unforeseen problems you ran into?

 

You might want to check here:
Engine Swaps - Ford Truck Enthusiasts Forums

 

If your state has emissions you may need to put a 24v in as they were what was in the equivalent in 01. In NJ the motor put in needs to be same year or newer to remain emissions compliant.

 

The previous poster raises a good point re emissions and that will likely be your
primary consideration. But briefly, the 12V will be MUCH simpler to swap, if only
due to the fact its all mechanical, vs. the more complex electronics of the later
24V engine. Performance mods are plentiful and easy to do for the DIY guy.

If you decide to go w/ the 24V, stay away from the dreaded Mexican "53" block,
produced in '01-'02 as I recall. It did not measure up to Cummins usual quality
control.

 

The 53 block was used throughout the years from 98.5 to 02, so any 24 valve should be checked for the 53 marking. I also believe that the block was cast in Brazil, not Mexico.

The 12 valve is simple, can make a TON of power and torque, easiest to work on of any diesel engine, and you can develop more power for less money than other diesel engines. Emissions requirements will be the hangup, as mentioned.
Aside from the 53 block (which has a section of the cast block that is thin, and prone to cracking from heat and stress- it is also about impossible to satisfactorily repair), the biggest issue with the 24 valve engine is the VP44 electronic fuel pump. That can be remedied by converting it to a P7100 mechanical fuel pump, which is used on the 12 valves. At that point, it will be as solid as the 12 valve, but within the year range of your truck. That may be the best route to go.