Check out SewerZuk's thread
http://www.steelsoldiers.com/deuce-...5511-all-stuff-i-did-my-deuce-right-here.html
He added a water methanol injection system to drop his turbo temp, and 395s to increase top speed. No matter what you do you will need a Pyro.
The basic issue you have is that you want to get more power out of a multifuel engine. To make power with a turbo you would usually decrease compression. However, in decreasing your compression on a Multi (Usually done simply by running a thicker head gasket, or some people have even run TWO head gaskets) you will loose its ability to burn multiple fuels.
Now, do me a HUGE favor. I recently lost brake pressure while driving because of a wheel cylinder. In the past I have done some scary stuff in the world of motorcycles and had some close calls, none of which were nearly as scary as loosing brakes in this 13,000lb cruise missile, and thank god I was in a parking lot. Before you so much as touch your engine, you NEED to pop open all six brake drums, thoroughly inspect them. If you can not say for certain that your brake lines and wheel cylinders have been replaced within the last 7 years, rip them out, replace them all.
This is not a joke, and its not your life to gamble. Before you make your truck faster, please be responsible.
/Rant
SOURCE: Lots of reading. My engine is stock.