I also have a 74 260z, when I acquired the car it had an air cleaner exactly like yours, including the holes.  They appeared original to me.  The air cleaner was not installed, and I did not get the flat top carbs, so that's about all I can help you with.

That's an impressive document zed head. Thank you. 

2 hours ago, Freez74 said:

I also have a 74 260z, when I acquired the car it had an air cleaner exactly like yours, including the holes.  They appeared original to me.  The air cleaner was not installed, and I did not get the flat top carbs, so that's about all I can help you with.

Freez, do you still have that un-used air cleaner? I'd be interested.

18 minutes ago, Dlobi said:

Freez, do you still have that un-used air cleaner? I'd be interested.

I wish I still had it, gave it to another owner some time ago.  I have seen them for sale on eBay.

I don't know when some of those modifications started coming from the factory (instead of being done at the dealers), but I think by the time they got the 74, most of that stuff was landing already done. Like the holes in the air cleaner and the fuel line insulation.

Dlobi, If you hadn't seen that 73-74 fuel modification documentation before, there's some really great stuff in there. And it's clear that a lot of the modifications and remediation work was being done "on the fly". I've heard lots of stories about heat related issues with the carbs, but thankfully I've never personally experienced it.

And not to turn this into a for sale thread, but I think I've got a spare flat top air cleaner around here that I could part with. Send me a PM if you're interested.