Note of caution with stainless steel fasteners. The galling potential is high with stainless bolt and nut. And if that happens, then you don't need to worry about a nyloc nut!.
Actually Milk of Magnesia is a very effective anti-galling solution
But you should check with Steve. My recollection is that, at least on the prototype, the engine was canted a few degrees. Not as far as the originals at 8.5 degrees.
But a subsequent lowering of the top of the driver footbox by RCR
may have addressed the carb clearance.
It is my understanding that the RCR use of the thicker aluminum for the tub renders it strong enough to eliminate the square structural tubing that Jaguar used in the transmission tunnel to connect the front and rear subframe. The RCR tunnel was designed large enough to accommodate an automatic...
Would it make more sense to use 4 studs on the bellhousing, with some taper on the ends, to facilitate easing the transmission into place? I used temporary studs as alignment pins when adding the trans just on the run stand.