Alright guys, I have an update. One of my concerns is the slant when the tanks are standing. So, I laid down the tanks and with a carpenters square and another ruler I measured the difference to be 9mm. After further inspection, I noticed I cannot cut out the boot so the taller tank sits lower. Therefore, the other option is to fabricate a spacer and build up the boot on the short tank. I bought a delrin bar about 1.5 inches wide x 10 inches long x 1/2 thick on ebay. I grinded down the bar to 9mm and just long enough to fit in between the ribbing of the boot and alas, my tanks sits nice and tall. In conclusion one tank is still taller than the other due to neck length and it is slightly noticeable. However, the tanks have a proper stance and I'm no longer worried about my manifold taking a beating. Thanks again.