MSA header

I never could figure out why Datsun made the center exhaust ports larger on their square port heads, but I do know that the tubing on headers has to be all the same length and diameter from the port to the collector in order for the header to work properly as a tuned header....in other words, MSA headers are designed correctly, and I have never seen any header that uses different size tubes at different ports. (on any header, not just Datsun headers)The round port Datsun heads all have the same size ports, so this remains a little mystery to me. You will be happy with the MSA header.

Same size tubes are nice and all,but they could at least make the opening match for the first inch or so. One buys a header for flow and that has to cause a lot of turbulance and cause those cylinders to run different. The factory manifold matches and the gasket MSA sent me matches. I guess I'll get my stock one coated.