Lucas 43D vs 45D ?

[sandman]

Can anyone shed some light on the differences between a Lucas 43D4 and a 45D4 sizzy?

Will a 43D fit into a 1275 A-series? (read: are they mechanical alike?)

Many thanks,

[MadMatt]

sorry but isn`t the difference simply one has vac advance & the other doesn`t???

i`m getting old & stoopid, so maybe i`m wrong

damn , don`t make me have to go & actually check