@neuro: it was me who asked you for the carb details 
anyway, i know that 4AG-E was a good engine but unfortunately mine came as the modest sprinter version with the 4K engine found in 76-79 corollas. it had a shorter gear ratio and final drive, which made it pretty quick in those days......
the Z setup is fun especially with the added slide at the rear end, allowing me to drift on demand.....
too bad that the shershah ppl don't recognize the carb from the car name (260 C or otherwise) and the only hope i have is to match it with a sample...
i've tried a couple of carbs similar to the one that came with my L26, but the primaries are always starving.....the reason found after opening the carbs was pure bad luck! they were damaged or clogged beyond repair....
if you could even attach a close up of your carb, it would really help......
thanx in advance.