I had my carbs off (which are Hitachi SU's off of a 240Z) and it gave me an opportunity to photograph the porting I did 30 years ago on my Stromberg head. The photo shows the entrance to the two ports. Miles Wilkins had recommended blunting the sharp edge at the entrance to the two ports. Unfortunately, I did not have a flow bench to do this porting, (although I have done a lot of head porting with my work). Basically, my approach was to make a bell mouth approach for the air coming out of the carbs and flowing into each port. Obviously, only one port flows at a time, so imagine making the air flow as easily as possible into one port at a time. The rest of the port is modified to minimize/eliminate sharp bends and blend changes in cross sectional area. Anyway, I attached the photo for reference in case anyone else is porting a Stromberg head. From my memory, the porting made a big difference in acceleration.
Another thing to do carefully is to match all of the transitioning parts from slightly smaller to equal diameter going from the velocity stack, carb, gasket and finally into the head. A stock engine has the balance tube assembly to match diameters as well. You don't want the air hitting a sharp edge, which would happen if the ports and carbs and gasket are not matched. The exhaust ports also need the same matching.
Many of you already know this, but if you didn't, it gives you something to think about.
I attached photos of the velocity stacks I use. I really like their appearance and design. They are available from the Z store. I think they will fit the Stromberg carbs as well. I don't think they would go under the stock air cleaner however.
