I am researching swapping out my '73 carbs on my 240z, to earlier '70 carbs for better performance.

I believe I will need to change the intake manifolds (going from square, to round ports?)? Is this correct?

Also, as far as the choke cable. I will need to replace this? Correct?

While considering this what swap might I also need to change some other components (delete some smog controls...live in Wisconsin) as I am sure some of you have more knowledge then me. I NEED YOUR INPUT.

Aside, in the future I hope to replace the head to an N42, as I believe it to be the simplest (bolt on upgrade) from stock.

Edited May 26, 201014 yr by mtbnathan
No replies. :(

If you're planning to swap an N42 head, I'd say do it all at once. Have the head freshened up, locate your manifolds and carbs and install it all at once. My car has an L28 with an N42 head and the SU's are connected to E88 manifolds.

I am researching swapping out my '73 carbs on my 240z, to earlier '70 carbs for better performance.

I believe I will need to change the intake manifolds (going from square, to round ports?)? Is this correct?

No. You can use the same manifolds now on the car. If the carbs you will be installing are from either a '70 or '71 (known as "4 screw" for the number of screws holding the dome to the body), you will need to bypass the manifold pre-heat (coolant lines), but that's all.

Also, as far as the choke cable. I will need to replace this? Correct?

Not sure on this one, but I think the '73 choke cables can be modified to work. In any case, the cables for a '70 will be considerably too short due to the difference in how the early cables were routed.

A lot of the guys we help with their modifications are also swapping in the earlier balance tube as well. Not necessary, just cleaner looking.