The class I pull in is called classic super stock. The tractors have to be 1970 or older, limited to one turbo, limited to 531 cu. in. and they all have to use the roosamaster injection pump.
A true super stock tractor has multiple turbos and they usually run huge injection pumps. Our roosamaster pumps will pump about 400 ccs but a superstock pump will pump atleast 1,100 ccs and some probably even more. The boost pressure in our class don't usually get over 50 psi but a superstock will run 200 psi of boost and maybe more. The superstock tractors usually have atleast 2,000 hp.
Our class is for the guys who want to have a little fun but don't have the big bucks like the big boys.
Here is a few more pictures. The turbo is not on but you can see how the tractor manifolds are different than the ld manifolds.
Here is picture of the tractor in its early stages. You can see the army green ld-465 engine in there.