'73 240z flat top carbs dilemma

[Dadsun]

Hi, all. I'm new to the Z community, but apparently jumped in with both feet... My first Z car is in that narrow range of '73 240z that has the original flat top carbs. Bought this from the original owner a couple of weeks ago. 

My dilemma:

As a newbie, do I try to sort out the flat top tuning and ongoing babysitting (as I've been told to expect), or do I opt for:

Option 2: ZTherapy carbs conversion to their $1300 "bulletproof" modified round tops. Pricey but probably the best long term option to keep close to original. 

Option 3: Weber DGVs in the $800+ range. Heard very mixed things. 

As for me, I'm pretty handy, but never had to tune a carb before. I've watched a YouTube on the flat tops. I'm game if I can get and stay on top of them, but if I truly have to continually tune them long-term then no thanks. 

Edited May 4, 2020 by Dadsun

[S30Driver]

If your goal is to be true to originality, option 1 is the way to go.   A long time member who lives close to me spent the time about 3 years ago restoring and sorting a set of flat tops for his 73.  He has had no issues since as far as I know and has no regrets on the move.   Maybe he will chime in  @Zup

Option 2 is of course the easy solution and can be done for much less is you source a roundtop set for Ztherepy to rebuild.

Option 3 will not get much support from members here.  The side draft webers are a totally different story.

[dutchzcarguy]

Welcome, If you restore the flattops to a new state i think just ones doing a tune-up should work.. Investigate if you can get al the new rubber parts etc. to restore them properly..  Tuning these flats is a bit more labour intensive but once done the right way (service manual!) it should work well... i think.. ? 

[motorman7]

I like option 1 as well...of course.  Here is a thread that I blogged during a Flat top resto.  I like the flat tops for the rarity and the fact that they are original to the car.  

 

 

[Dadsun]

This looks like the set:  zcardepot.com: carb-rebuild-repair-kit-flat-top-carburetor

 

[Dadsun]

A couple of pics showing what I'm inheriting. Build date is 10/72.

[w3wilkes]

I drove a '73 with flat tops for about 20 years until it rusted to death. I found the flat tops to be very reliable and required little to no attention. Once tuned they will just keep going.

[Dadsun]

Well, y'all are giving me some encouragement to try to hang with them. Not to mention the Z therapy prices are steep. 

@motorman7, I'll set aside time to read through that long thread of yours. 

[7tooZ]

2 hours ago, Dadsun said:

Well, y'all are giving me some encouragement to try to hang with them. Not to mention the Z therapy prices are steep. 

@motorman7, I'll set aside time to read through that long thread of yours. 

Hey some good feed back. As mentioned earlier I didn’t think you would get any positive response to the down draft dual Weber idea.  As I said earlier Keep the carbs you have if you feel like they working okay. Drive that car and learn it idiosyncrasies and study the knowledge of those here here are familiar with them.  The easy route is to immediately go to the Ztherapy route. I will be interested in your updates on the gas tank refurbish.  Good luck any enjoy the process 

[Captain Obvious]

Flat tops FTW.  

By the way... You got a boat?

[Dadsun]

I don't have a boat. Well, my kids have a little pirogue for the pond, as we call it down here.

Am I getting too ambitious if I swap out the K&N for a pair of these in the process?  https://zcardepot.com/products/air-filter-set-k-n-racing-filters-240z-260z-73-74?variant=18837653422193

 

[Captain Obvious]

2 minutes ago, Dadsun said:

Am I getting too ambitious if I swap out the K&N for a pair of these in the process?

Yes. For now. Get it running reasonably well before you go trying stuff like that.

I'm not ready to talk you through modifying where you get clean air for your idle mixture air, or what to do with all the other stuff like the idle compensator and the anti-backfire valve and the air pump supply, and the, and the.....