Since I have never dealt with a 4-barrel conversion I can't say that I am for or against them. However, the inline 6 in my ford pu has a very similar set-up, one downdraft carb feeding all the cylinders through an intake manifold. I never have any problems with my #1 or #6 plugs. Why is it a problem with the z's?

Dan

My guess would be that your Ford was originally designed to run with a single carb in the downdraft configuration. The Datsun was not. It was designed with twin sidedraft carbs.

If you do a search you will find that not many people have had good luck with them on thier Datsun. Loss of power is the most common complaint.

$.02

yea, i've read plenty about that. what you said makes sence, beining designed for the single carb from the get would answer my question.

thanks

dan