We have clearance Clair-ence... sorry Airplane movie joke.
No, with the polyeurethane spool mounts it stays put. I may add a "strap" for insurance.
Driveline angle is just about perfect or as close as I can currently measure. Once I get the rear axle, exhaust headers, driveshaft and everything else situated I will check angles, heights and all the other clearances. If possible I may notch the spool mounts and drop the nose of the engine about 1/4" and maybe even shim the transmission mount up a little. This will slightly increase the air cleaner clearance and reduce the engine angle.
With the current ride height I was measuring 2.5 degrees at the crank, does not get much better than that. If I drop the body 1" relative to the axle that will add about 0.5 degree at the crank relative to the body. Still OK, but then will depend on the relative height of the front U-joint to the rear U-joint. If the driveshaft is level, or runs downhill to the differential then no problem. If the pinion is higher than the transmission yoke then that is an issue. I just have not looked yet, maybe just worrying about nothing.