Thread: Will a '83 model dizzy be a drop in fit for a '75?

Agree. This sounds the easiest, as AFAIK the timing cases didn't change.
However you never know with LR.

If you do the oil pump mod, make sure to completely fill it with vaseline before attempting start, and a good way is to get a shaft eg all thread cut a slot in the bottom to fit the blade on the new type pump shaft and turn with an electric drill down the dizzy hole until you get oil presure.
Regards Philip A

Originally Posted by PLR

I agree with DoubleChevrons reply .

You seem to have the information but have trouble putting it together .

The figs you give for the pump gears tell there is a variation of over 4mm .

The bottom plates are flat the extra distance is inside the pump cavity , if you fit later taller pump gears to an early timing cover the gears can`t rotate .

There are 2 gears one idles on a post the other is at the end of the distributor drive .
Changing the drive from one type to the other requires not only the changing of the drive type but also the pump gear or pair of gears .

Nunawading ignitions , i think it is , can change the diaphragm in your vacuum advance , they will return post it . Don`t remember the cost .

Thanks PLR.
I understand the difference between the gear heights and the drive types. Likely didn't express myself correctly.
There is a kit available to use the later gears, which is really a simple spacer plate, an extra gasket and a set of longer (later) screws.
Buying this kit gives the extra length required for the gears to clear the case, THEN buy the late type distributor drive gear and it should all come together.

Already been in contact with Performance Ignition Services at Nunawading.
I spoke with Peter, twice.
Good folk offering helpful, accurate information and service.

Cheers,
Richard