I CAN’T DRIVE 145mph

Put it up on some good jack stands and start running through the gears and see what speed & rpm you are running, no wind resistance!
Aaah I remember now, About 6 years ago I put in on a Dyno at MATS Las Vegas and it topped out at 155 and it would not hold at 5500 rpms it would drop back down the speed would stay but the rpms would not go up past that.

I had 323 gears and I had the overdrive on, I did not have the switch hooked up to turn it off.