Jump to content


changing out flattops with earlier SUs


Recommended Posts

I have a 73 with the stock flattop carbs on it. I was thinking about going to the round top SUs. Are the round top SUs from a Rodster compatible with a 240Z? Or do I need to stay with the SUs from a 240Z. And do I need to or should I also change out the intake manifold? What are some of the things that I need to keep an eye out for when doing the switch.

Link to comment
Share on other sites

Atomrat: I can't answer the specific questions you asked, but I can tell you that the linkage for the round top carbs is different from the stuff you got on the flat-tops. You'll need to get linkage as well as carbs is what I'm saying.

Good Luck


Carl Stahlnecker

72 240Z "Bambikiller"

HLS30-55703 11/71



Link to comment
Share on other sites

I made the conversion you are asking about. I don't know about the roadster question because I do not know what SU's are on that car.

The correct SU carb is the Hitachi HJG46W. Mine came off of a '72z but had leaky thottle bodies. I remidied the situation by calling Scott at Z Therapy and getting a reworked set from him with a rebuild kit for the remaining parts and pieces. Discard the intake manafold as well or attach it to your boat for an anchor. I have cannabalized some of the manafold 'plugs' and fitting from the flattop setup but that all.

While adjusting my emmision control systems a bright flash of light initiated a consise eurika moment and I trashed the enitre system as well, with substantial increased performance and cooler high RPM operation.

Good luck. Talk with Scott, he is very knowledgable about these mods although he will always try and sell you the "shiney" ones.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.