Maynard replied to MissingParts706's topic in General IH
The spring was eliminated by IH rather early on on 06 series production. It was recommended via service bulletin to remove the spring.
Some people would rather have it original even thought it would work better if modified.
Maynard replied to Missouri Mule's topic in General IH
I have two different Neuss Engine manuals from IH, the attached images of valve specifications are from those manuals, niether give the specification for the intakes you listed as from Blue Ribbon Service Manual.
The base transmission is 18 speeds, can have creeper or overdrive but not both.
19 speed economy restricts top speed by reducing engine rpms, the 19 speed 30 mph option is only available with front suspension.