My racecar runs an offset motor 50mm and I have never experienced any driveline vibration or premature wear. It is also set back 300mm so runs a short driveshaft

There were many cars up to the 1950's that used a torque tube drive instead of the Hotchkiss driveshaft that is universally used today.

These torque tube drives used only one universal joint & it was located just behind the gearbox. Engineers knew even back at the turn of the 20th century that you do not experience any detectable velocity fluctuations from the uni if the deflection is not more than about 7 degrees from the straight & narrow, although 5 degrees would be prefered. Even this figure allows a 10 degree sweep & this was within the normal movement of the joint in this application.

If you can keep the angle of deflection, when seen in plan view, to within about 5 degrees, you should be fine.

What size bore are ou using ?

Also I think you'll find 33mm exhaust valves are to big you'd really want 30.5mm as a max.

could you slant the motor at all to miss the brake-cylinder-thingy? what the name for it i im not thinking today

Universal joints work fine if both shafts are parallel. In this case the output of the transmission will not be parallel to the input of the differential. I don't know how much misalignment you can have before you start to get driveline vibration.

Yes, the 40mm valves are on the large size. Whoever did the work on the head put in large seats and valves, opened up the valve pockets, but did not open up the ports to match. I'm planning on opening up the ports and intake manifold just enough to match up with the Datsun comp manifold gasket. Maybe slightly larger than the GX head but not nearly as crazy as some of the race heads I've seen here and at Dan Hall's shop.

Would you need a CV-joint? Lots of jeeps and other trucks use offset differentials and they just use U-joints.

40mm intake valves is very big, I assume you are building it for high RPM? Then 30mm chokes seem a bit small.

I'm in the process of building up an A15 motor for the street/autocross car. The head is an A14 oval port with 40mm intake, 33mm exhaust valves. Carbs are dual 40DCOE Webers using 30mm chokes for the first tuning go around. Cam has not been chosen yet.

The thought I had today is what about offsetting the engine to the right a couple of inches? The car is a LHD model so space is very cramped on the carb side of the engine bay. As far as I can see, this would do 2 positive things- Creates more space for the carbs and aircleaner setup and would help balance the car weight wise (helping to offset my 190# on the left side of the car).

As the sedan was an automatic model there is plenty of room in the transmission tunnel to swing the front of the engine to the right leaving the output shaft of the transmission centered.

As I have to have a drive line fabricated to fit the 63A dogleg 5 speed tranny in the car, it would not be too much more to have the front of the drive line setup with a CV joint to deal with the angle caused by the engine being offset.

After a quick look at the engine compartment it looks like the only change to the engine would be to use a short oil filter to clear the front antisway bar.

Thoughts?