early or late model?

[ffmedic]

I want to replace my fuel pump and change to electronic ignition however I keep seeing different parts for early and late model A4s. How do I tell which one I have. I have a 1973 Ranger with the A4.

[joe_db]

Assuming the engine is the same year as the boat, that would be a late model.

[ffmedic]

Thanks Joe. The engine is the same. I appreciate the info.

[roadnsky]

Early or late model? How can I tell? What difference does it make?
Most parts are interchangeable between early and late model engines. However, a few parts (particularly some of those used in fuel, ignition, and cooling systems) are unique to early or late models.

If you have an original engine from the mid-seventies or later, with an oil fill tube over the flywheel housing in front of the engine, you can be reasonably sure that your engine will require all late model parts.

If your engine does not have an oil fill tube over the flywheel housing, it may require a mix of late and early model parts. You will therefore need the following information before ordering:

1. To order ignition parts (including the "Ignitor"), you will need to know if your distributor was manufactured by Delco (used on late model engines), or by Prestolite (used on early model engines). Prestolite distributors are distinctively smaller in size, and their condensers are mounted on the outside of the distributor housing.

2. To order cooling system parts, you will need to know if your engine has a thermostat housing (a small dome-shaped casting) located on the front corner of the head, nearest the starter. This thermostat housing would indicate that your engine has a late model cooling system.

3. To order carburetor parts, you will need to know if your carburetor is made of aluminum or cast iron. Aluminum carburetors were used on late model engines. All carburetors were manufactured by Zenith or Bendix, so the manufacturer does not help in determining your carburetor vintage.

4. To order gaskets, you will need to know (1) and (2) above, plus the shape of your transmission cover. Late model engines used a square cover, and early model engines used a rectangular cover with a curved top ("tombstone-shaped").

Also, look for a serial number:
On late model engines, the serial number is on a flat spot in front of a "boss area'" in the casting of the block, directly above the oil fill tube over the flywheel housing.

On early model engines, the serial number is on the front side of the block directly up from the starter.

[ffmedic]

Great information thanks for that.