Fuel Tank Swaps.

[Arnie]

I have a different set of carbies on the bike now which don't like the fuel pump so currently I have the fuel direct from the tap but I know that if my carbies leak I'm in trouble. Mark made a comment that the petcock is different to the 87 models (my fj is 3CV 1990).
My question, is there a vacuum petcock that fits my tank direct.

Don't know which vacuum petcock might fit.  You could probably go to a large wrecker and start searching for one with the right mount pattern.
Alternatively, you could put a solenoid valve in the fuel line that shuts off when the ignition is off.  (your +12V wire would go to any of the brown wires in the loom)  I used an 1/8" one from bestboss2011 (off ebay) that cost under $15 including postage,for my chain oiler, but I don't see any ads for them now.  Here's an alternate more expensive seller's wares:  Item number: 110904549377

Arnie

[RichBaker]

None of the vac petcocks will fit. The fuel-pump version's base is a lot smaller.