One thing that should be readily apparent to any astute head porter comparing the 194 head to any of the open chamber heads is that the chamber for the 194 head is designed for an engine that has a bore of only 3.562". But if you don't know anything about the dynamics of how those things interact between head and cylinder, you will blindly follow the countless sheep that have also made the mistake of those before them. Placing it on an engine that has almost a 4.000" bore places the edges of the chamber way too far away from the cylinder bores to breathe freely and greatly shrouds both the intake and exhaust flow. The casting just isn't thick enough to allow it to be corrected when placing it on a bore of this size. This can often be traced back to the "copy cat" syndrome of, because it works for a small block, it will work on this engine. As many professional engine builders have found, this isn't always true. The reason the closed chamber head swap on the small block works and it doesn't on the 6 cylinder, is because like the open chamber head for the SBC, the closed chamber for the SBC is also designed to be used on a 4.000" bore, thus the smaller chamber does not restrict or shroud the cylinders breathing ability. And for the 6 cylinder, the open chamber head is always going to be the better choice. All of the top 6 cylinder head porters and engine builders have known this for over 40 years. If anyone tries to sell you the small chamber head swap as being the better choice, they either know that many hotrodders have sipped the "Kool-Aid" and have bought into the "because it works for the SBC" mentality, and are simply taking advantage of you being naive to know any better, or they themselves have sipped the "Kool-Aid" and have no clue either.
