[Healeys] Help with BT7 (new thread - I got bounced again!!!!!)

[Per Schoerner]

Bob
Yes, that's right, the rear ends are different too, for example a 3000 
with overdrive has the same rear end ratio as 100/6 without overdrive. 
When you install a 3.545 rear end in an overdrived 3000 you get the same 
ratio as a 3000 without overdrive, but the speedo from a non overdrive 
3000 will probably not show the correct figures, because the speedometer 
drive is probably different.

Per

Bob Spidell skrev 2012-08-30 02:07:
> Yeah, looks like the speedometer drive pinion assembly is different
> between earlier and later cars (according the Moss catalog, anyway).
>
> Also, IIRC the non-O/D cars had a taller rearend; between the two
> differences a different speedo would be required (or speedos can be
> fitted with different internal gearing--that's what I did when I
> installed a 3.54 rearend).