I had a buddy with 74 long bed pickup that looked like total crap. He had 600hp bbc chevy in it then added a 100 shot of nitrous. He used to destroy almost everyone. It got to the point when the cat was out of the bag and no one would race him. I remember being at the illegals and hearing some kid with a new BMW M3 say "HELL NO I'M NOT RACING THE FARM
TRUCK!!"
Oddly enough one of my other friends had 11 second Buick GN and no one knew what the hell it was. The Honda were the most baffled by it.Later he got an 03 Cobra, not a sleeper but any means but still the kiddies would just asume it was just a GT. We really should have started racing for money.
Same thing with my 5.0 92 Mustang coupe. Everyone thought it was 4 cylinder.