this came off my a14 I think it is an (a14 oval port "h75") Tech section a-series cylinder heads. it has 37mm-30mm valves and 28mm 34mm ports as well as 360 open low combustion chamber. did these come out with double valve springs? and is there much more i can do to improve it?
Clean up the manifold mounting face where it appears there may be some small water ports there. You say this head is an H75? I know the H72 has the open chamber, and no water ports. The A14 manifolds still use a hot box system to heat the carb. All the A14's I've seen have had the H72. I took an H72 in to get shaved, and guy said I was wasting my time. He said the open chamber head will never be a perfomance item. The best head of the easily available variety, IMO is the H89 head from the A15.
this head has h89 and 605 printed on it, i thought that this was just in the same series as the h75 as i could find no info on the h89. is the h89 a better head? there are no water ports on the mounting face
There wasn't really an A14 GX engine. There was an A14 twin-carb engine with name "A14T". It was basically a standard A14 closed-chamber head but with dual valve-springs. The Twin-Carb manifold has the regular oval size, much smaller than a A12GX or A12T Ovals.