Has anyone else found the gearing article by Paul Huryk to be a little.... off?

https://www.thirdgen.org/newdesign/tech/gears.shtml

I'll show you why I think it's off.

He said his car has 500hp @ 5500 rpm's and runs 120mph in the 1/4.

Data:
25.5 inch tires
500@5500
3.42 gears

Alright so the 3 equations he gives are 1/4 mile speed, optimum gear ratio and top speed.

Quarter Mile: (Using his data)
Using his article you would multiply 5.5 (comes from 5500/1000) * mph, mph comes from the mph/1000rpm chart he gave

(RPM/1000) * mph

5.5 * 21.82 = 120mph

Optimum Gear Ratio: (not important to this article)

Top Speed:
Using his article you would multiply rpm by the height, divide that by 341.73 (a constant he gave) then divide that by the rear divided by the overdrive gear

((5500*25.5) / 341.73) / (3.42 * .7) = mph
(140250 / 341.73) / (2.394) = mph
410.412 / 2.394 = 171.433

So 171mph top speed like he said

Alright that's fine, now compare it to the stock 89 RS camaro automatic.

Data:
25.5 inch tires (he said that was stock)
170hp @ 4400rpm
2.73 gears

So following his equations....

Quarter Mile:

4.4 * 27.35 = 120.34

27.35 came from his chart.

120mph at the end of the 1/4 mile, just like his

Top Speed:

((4400 * 25.5) / 341.73) / (2.73 * .7) = mph
(112200 / 341.73) / (1.911) = mph
328.3294 / 1.911 = 171.8102



So by his article his 500 horsepower 3.42 geared car will reach 120mph at the end of the quarter mile and my 170 horsepower 2.73 geared car will also reach 120mph at the end of the quarter mile?

And his car will top out at 171 and mine will also?

I'm not trying to prove him wrong, I'm wondering if the equations he gave are right. I've been sitting down trying to figure out the gear ratios and top speed compared to quarter mile then I come across this and it tells me our cars are the same except his has 3 times the horsepower then me.

I'm pretty sure my car won't get up to 120mph in the quarter mile. Am I missing something to his equations?