I think your convertor is slipping,lol.
No slippage, it is a stick. tire is actually a 235/60/15 which is approx 26.2" tall. RPM is approx because speedo not to accurate. Where i live is mostly 45-55 speed limit, which means I'm doing 50-60 mostly. the cam and gears work well for may application. Better cam and gears , yes,but this is a spirited daily driver. An O/D would change things up a bit. A little more cam ( thinking of going to roller) and gear, 3.91 or so. But to do that need more tire which means narrowing rear end and upgrade to rear disk while I am there,because the car is set up for road course. Also to keep the look of the car custom cop wheels for the wider tires. So the little change for me would be a big $$$ at this time. Any suggestions are always welcome.