Does anyone know or why there are 2 type of Super Rams? My plenum is 2inches tall an others is abour 2 1/4in tall. Even the runners are about an 1/8 shorter. How I know this is because the bottom of the throttle body where the vacum fitting is hits the top of the thermostat housing. The taller plenums don't. I had to use a carb housing and reroute the hose using a flex hose to go to the radiator.


The other question is- is there a difference in HP & TQ between the two?

 

There is one made for the LT1 cars, it has a shorter plenum, too clear the cowl on the 4thgen cars. Gives up some power to the taller plenum. I think i read it was about 5/8 shorter in height. Maybe thats what you have?

In Johns book he states that the shorter plenum costs around 10 horsepower at the peak. Because of the tighter radius the air must negotiate entering each inlet runner and the reduced plenum volume.