Originally Posted by cth350

Everything you ever wanted to know about your 4A1 carb can be found in the 1973 introduction to service manual. This isn't the most easy book to find. I can email you scans of the relevant pages if you need them. Let me know which year and make car you have and I can see if a later year's intro manual has more stuff.

If you haven't gotten it yet. Pickup the dealer service manual for the M110 motor and the relevant manual for the chassis. They are the most complete set of service procedures you'll ever see in print. A CD rom of all the books is available too if you have an aversion to paper.

I know of the following possible forms of M110 fuel delivery:

- The 4A1 carb
- EFI (D-jet)
- CIS
- Weber conversion
- Holly conversion

As noted in the previous post, converting your car from carbs to fuel injection requires a change to the head. If you already have a replacement head, then most likely it was a fuel injected head with the ports sealed shut, since the engine manual says that was the only kind of head supplied as spares.

-CTH