T120C

[Larry Biagi]

how can I identify the correct head for a T120C ? while J.R. Nelson's book show E5727 for the T120C and E5348 for the T120 all the heads I see show E3663 - thanks - Larry Biagi

[L.A.B.]

Larry,

Are you referring to a number that is cast in?
If so then it may not be the actual part number but the number of the blank casting from which different variants of head (for example) could be machined.

You could try measuring up the valves and intake ports to see how they compare?  

[larry biagi]

L.A.B. - yes , the E3663 refers to the cast in # - Is the only other way of determining a difference in the head to actually measure valve sizes and intake port sizes ? - and does the cast in two digit number found in the opposite area on the head refer to the year of the bike that the head came off of - thanks larry

[L.A.B.]

I really don't know about that but possibly TBS or others here will be able to give you more information?  

[TBS]

I think that there was no difference in valve or inlet/ exhaust track sizes, apart from the modification  for all models from 1964 to the inlet valve size of 1 19/32" and exhaust of 1 7/16".
The TT version was called a T120C TT from '63 to '65, and then the C was dropped in '66. Compression ratio was 11.2 :1  in '65 reduced to 11.0 :1 in '66

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