Quote: You're kind of stuck with the vertical rear u-joint location where it is. That's determined by the type of rear and tire size. A 9" with a 32" tire is around 13 3/4" off the ground. If you are able to install the engine/trans assembly in a location that allows the operating angles to be correct, while having the trans centerline parallel with the pinion centerline, that's great.
The "chart" is great except that it doesn't consider that the pinion centerline could be higher than the trans centerline with the front of the engine higher than the front u-joint. I've worked on plenty of lowered and backhalved cars with the engine/trans on stock mounts and angled down a couple of degrees or more front to rear. In order to get the pinion parallel with the trans, the pinion angle would have to go positive (definitely not acceptable). A lot of these cars end up with a "broken back" configuration to keep the pinon angle negative.
If the car was built with the driveline stringlined from the front of the crank, through the center of the trans, to the center of the pinion, it makes it easy. Most cars weren't and you have to work with what you have to maintain the pinion angle where it needs to be. Not a lot of wiggle room with the pinion angle. At some point, you have to live with it or move the engine/trans mounts. Stock front clip and/or stock floors? That makes it even tougher.
As long as the trans and pinion centerline angles are equal and opposite what does it matter if the pinion centerline is above or below the trans centerline?
