Does anyone know..
Will a A15 sump fit onto a A13 block?
Any known clearance issues or stud/bolt alignment problems?

you need to have the thermostat to keep the coolant in contact with your bores and other engine internals long enough for effective heat transfer. Your temp gauge will not be giving you an accurate reading of the temp of your engine. The coolant will run cooler, but the temp of bores and such will be higher. If you dont want to fit the thermostat, at least cut one up and just put the backing plate in to give you some restriction to flow.

Electric choke just gets hooked onto ignition power, then adjusted to suit your climate. I lived in Darwin so it was only on about 2 thirds at cold. Make sure you push the throttle to the floor once before you start it cold to reset the choke. If by the fuel sensor your talking about the anti dieseling solenoid, just hook it to a power source thats active at ignition 'on' and 'start', but not ignition 'off'.

It performed the same as the 32/36 DGV I had on there before, although alot smoother. The fuel consumption was about the same as well, still got 500+ K's out of 40 Litres as long as I wasn't on the secondaries all day.

They came out on XE/XF Falcons. I used one on my A15 and it worked a treat. might need to swap the jets and air bleed tubes in the secondary circuit, as its off a 4 Litre motor. I took the jets and tubes out of the primary side on another one of the same carbies and put them in the secondary side of mine and it was pretty close, just had to drill the new seconday another 0.05mm from memory.

as racinaround said, get one that goes both ways, BOC gasses also offer hire bottles on a daily basis, so if you get everything ready to go and hire a bottle for the day, you may end up with a better finished product.

z145a is correct for a series engines

a small tear rolls down my cheek

PM sent

I've got one you can have for a six pack of Bundy cans, will even deliver, I'm in Toowoomba as well.