Greetings:
The following is general information and observations through our experience.  
The Farmall engines are 4 cylinder engines that have a long stroke with low compression.  They were developed to breath very well for low speed power and torque.  All other 4-cylinder farm tractors are similar in design.  This is a very good design that allows high torque and moderate horsepower.  
The cylinder head on these engines were designed for exceptional breathing for low speed operation.  The port arrangement feeds two intake valves on adjacent cylinders in a connective port.  For example a single intake port divides inside the cylinder head and feeds two cylinders. This is a very good arrangement for low speed power and torque.  All of the other four-cylinder low speed tractor engines were of the same design. 
The number two-cylinder intake valve opens drawing fuel/air from the intake manifold.  Once at the bottom of the stroke the number two-intake valve closes and the number one intake valve opens and continues to draw fuel/air through the same head port.  This design takes advantage of the fast moving air column to adequately charge both cylinders making a very efficient and powerful low speed engine. The same events occur between cylinders three and four.  The firing order on all four-cylinder engines is 1-3-4-2.   
A turbocharger is an exhaust driven supercharger.  It takes advantage of exhaust heat and pressure that is normally lost in the air.  A turbo that delivers 10 plus pounds of pressure on a low compression engine will cause the engine gain a substantial amount of power and torque. Remember these engines breathe exceptionally well in stock form. With a low compression and long stroke engine the power output can be quite astonishing.  This can be achieved without increasing the engine speed.  If the engine size or speed is increased without raising the compression ratio the horsepower and torque will increase greatly. The design of the stock Farmall engine is ideal to take full advantage of turbocharging.   
At 10 pounds intake boost the intake valve opens and the piston is forced down on the intake stroke.  At 10 pounds intake boost a 4-inch piston will exert a force of 126 pounds on the piston on the intake stroke.  This force will offset the additional compression pressure of the other piston thereby assisting on the compression stroke.  The engine will run smoother and cleaner.  
Modern turbochargers are very reliable and the Garrett turbos used on our kits have a standard warranty of one year or 100,000 miles.  With a little care and an oil change at regular intervals a turbocharger will give many years of trouble free service.  
Keystone Turbo’s Farmall M kit is complete.  There is nothing else to buy.  The carburetor and the exhaust are in the original position.  The buyer must install a ½ oil drain and installation instructions are included.  No modifications need to be done to the engine or tractor.  On some models the front hood brace on the left side may have to be removed. 
The kit includes the intake and exhaust manifold, Garrett turbo with wastegate, intake pipe from carb to turbo, manifold gaskets and carb gaskets, oil lines with fittings, bolts and MAGNUM stickers. 
Facts about the turbo kits:
         -The turbocharger kit is a bolt on kit with no tractor or engine modification.

         -The turbocharger kit will increase horsepower and torque to modern

           standards. 

         -Other means of increasing power and torque is much more expensive and

           time and labor intensive. 

         -The turbocharger kit can be unbolted in less than 30 minutes with no

           expense if the tractor is sold.   

         -Tractor collectors can enjoy the high power turbocharger system and return

           the tractor to stock in less than 30 minutes.  

         -Expensive machine work and hours of labor cannot be recovered.  

         -The turbocharger kit will fit Farmall tractors of various engine sizes. 

         -The turbocharger kit will provide additional power for farm work. 

         -With a turbocharger kit an antique tractor can do the work of a modern day

           tractor thereby saving thousands of dollars.  

Thank You 
Franklin Duddy & Mark Duddy