We simply got rid of the rubber motor mounts and notched the crossmember. For the transmission mounts we simply made spacers and used longer bolts.

The reason we did that is becuase I'd repeatedly put the car on two wheels. Lowering the engine cured the issue.

Mine is in a totally different car, but the handling definitely improved when I put the engine in low and further back in the car. I had to make a custom oil pan to get it lower. It seemed like a good idea to drop the transmission as well, so I lowered it half as much as the engine (about 6cm for the engine, 3-ish for the transmission.) I fabricated mounts using belleville washers as the vibration isolation: a stack of six between the engine mount and the frame, and then another two above that, so the engine can move a bit in either direction. On the (datsun) transmission, because it's so light, I just had two bellevilles above/two below. Each washer gives me about 3mm of movement.
If you were worried about the driveline angle, could you tilt the differential a little?

what some have done:
1. Notch the engine crossmember, so that the unmodified oil pan will clear lowering

2. Fit shorter engine mount insulators (or eliminate them, "hard mounting" the engine, as some race cars do)

3. Use longer bolts and spacers for the transmission crossmember to lower it


#3 is optional, you don't have to do it, but at high rpms a little vibration may be introduced via the driveshaft angle. But lowering the gearbox the same amount will make it aligned correctly

I lowered my A14 and A15 by custom engine mount brackets and hammering the Sump on a dummie block
as I wanted more clearance when closing my 1000 bonnets. Handling was probably worse than with orig A10.
Driveshaft angle is not such an issue as many bike engine conversions angle shaft like crazy.

I always wanted to tilt the A series to angle the inlets for my bike carbs but starter motor limited
the amount of lean somewhat and would have to get rid of the leaf sprung in the front crossmember which
is not an issue with the later A series cars. In Japan a kb10 did angle the A15 but used coil overs.

One for the race guys here...
Has anyone had any experience with lowering the motor in the car and if so how did you go about it?
I am particularly interested in whether the gearbox was lowered as well and if so did that have an adverse effect on the driveshaft angle?
Cheers
Dave