The only time I was ever checked by tech inspectors was in Napierville, Canada, and it was because of who I was running. It was in ‘72 with the Fugitive and I was running Tom Maras' Moonshot injected Chevelle. The tech guy went over the car with a fine tooth comb and wasn't going to allow me to run because of no padding on the roll bar. I finally went to the owner of the track and explained I was going to load the car and leave. 

They still made me make a single to "prove" I knew how to drive the car even though it was NHRA sanctioned and I had a NHRA license to drive wheelstanders. Bob Riggle "Hemi Under Glass" and Bill Shrewsberry "LA Dart" had signed off a year before for me to get it in addition to the NHRA Division Director and the track manager at Houston (when Gil had Houston). That's one of the few times I knew the fix was in.

However, the two runs we did make against each other, I won by as big a margin as possible. I probably ran a second and a half to two seconds, and 10 to 15 mph faster than he did. It wasn't pretty for him at what he considered one of his home tracks. That's one reason I will argue that on very few occasions, the results were at least attempted to be manipulated.