[Healeys] clutch interchangability

[Eric Frenken]

Healey specialists,

the 6 cylinders started life with a 9" clutch, while on the 3000s this was
increased to 10". Sometime in 1963 (on the MK IIa) this was changed to 9.5"
(diaphragm spring type) and later in 1964 reduced to 9". I thought I had
read somewhere that the earlier (pre MK IIa) model clutches can easily be
converted to the 9.5" diaphragm spring type clutch by simply exchanging all
3 clutch components (driven plate, clutch cover and release bearing).

Lately I tried to install a new 9.5" clutch into a late (center shifter) BT7
but found that the clutch cover doesn't fit. The holes on the outer edge of
the original 10" clutch cover (which take the screws to the flywheel) are
about 11 5/8" apart (measured across the center of the clutch cover), while
these on the 9.5" cover are only about 10 5/8" apart.

My question is, do I have to change the flywheel as well and which other
"surprises" do I have to expect? Is there a clutch set I could use on all 6
cylinders?

Thanks,

Eric