are they really that awful? the car i have is complete and unmolested, so im inclined just to restore it to factory tune.

but i dont want to waste time and money rebuilding the flat tops if they are crap.

thanks,

-james

They really aren't that bad, but you need to do a couple things to make them better. Like ditching all the smog equipment if you can legally do it, and then blocking off the water to the intake and carbs. I had a 73 that ran fine with the flat tops after doing these things. The flat tops aren't as good as a set of the early round tops, but they would be better than the downdraft Webers IMO.

Good luck....

After a lot of trouble trying to tune them, I finally ditched the flat top SU's on my 260Z for a set of round tops. I wasted the money I spent on a rebuild kit & new needles, just couldn't get them tuned properly. I'm not sure what the problem was - it was tough getting the fuel mixture set properly.

The round top SU's made a big difference in performance for me. I bought them used & put a kit in them.

I have a Z friend that has a '73 with flattops that runs well. I don't remember if it has all the smog stuff or not. But I think if they work then leave them alone. Some environments will bring out the worst in them while others will not trouble them as much. I am talking about things like ambient temperature, altitude and driving patterns, etc. One of the big problems with the flattops is finding knowledge and parts. Most people change them since the roundtop SU switch is so cheap and easy. Although, I have seen many more Z's in the wrecking yards with flatops than SU's these days!

Happy holidays!

If you have a concorse origional car by all means keep the flat top units. If you don't have a garage queen and want to drive the car and enjoy it , keep the intake and dump the carbs and aircleaner and go to round tops. they run better and are easy to work with. Get the stock air cleaner from a '72 also.

Hi all,

This is of course my opinion and not one shared by many of you but i'm keeping my flat tops on my 260 purely because theres nothing wrong with them. There is of course a lot of difference between these and the early dome top carbs.

The water jacket is a bone of contention because the dome tops don't have it but keeping in mind that the carbs sit directly above the exhaust this does keep them at a constant temp.

Intergrated fuel bowl under the throttle body looks different but does it mean the carbies are getting any more or less fuel than the remote fuel bowl on the dome tops.

As for the smog gear that covers these carbs well thats a sign of the times we live in.

Yes these carbs are a bit harder to tune with the smog gear on them but with a bit of persistence they can actually run very well.

Mine do.

Alan.