Some day soon I will replace valve stem seals. I plan to pull all plugs, rotate each cylinder to TDC and then do that pair of valves. With the cylinder all the way up, I should not have a risk of dropping a valve into the cylinder.

Does this approach sound good?

Thanks, Mike

 

Mike - The pump should have been the same from 1980 through 11/84.

 

This is what I took out.

 

I'm sorry, but I don't know what the pump should look like. All I know is what I read in the catalog.

 

After looking more closely at the truck, it would not have made a difference if I used the 79 or 80 pump. The flange is reversed on the 80 pump from the picture above. But the mounting spot on the block was obviously made for either design.

 

So, which will you use?

 

Carter fuel system web site has dimensions for 1979 and 1980 fuel pumps. They are different.

I have both a 79 and a 80 coming into parts store Monday.

The one that is closest to what I took off is what I will put on.

 

Let us know. I hadn't heard of the fuel pump being different, and the catalog says they shouldn't be. But, there are errors in the catalog, for sure. And when I find them I make notes in my copy, which then usually shows up on my web site.

But, do you know that the engine is original to the truck?

 

I don't have full history on the truck. Everything appears as it would with an old truck with light mileage. I don't see much out of place. I can tell left front fender was replaced. Left inner fender is cracked in several places as you would expect with a minor fender bender. I will get to cleaning all the grime off the engine and recording the engineering and casting numbers. First I want a reliable driver. Even then I will not know that this is the original engine. Any advice on how to tell if this is the original engine is very welcome.

 

On the fuel pump, it appears the mounting surface on the pump could be either pattern, as the block is surfaced to support either. I think the pump I got at the auto parts store had been put in the wrong box. The plastic sealed bag was not sealed. The number on the pump did not match the number on the box, in the box were three gaskets. The height and length were very much shorter than the one I took out. There are new ones due in on Monday and I will know more after inspecting them. I am suspicious that it is possible a 1/80 truck will have a 12/79 engine.

I also do not understand the air pump setup. It appears to dump air into a single large port directly under the carb. Do you know if this is correct?

 

I don't know about air pumps on those. I'll look at the catalog, but there's another thread on here about air pumps and things changed several times over the Bullnose years for that engine.

On the fuel pump, I'll bet you are right about the pump you got. Too many people return things in the wrong boxes. I usually refuse to take a part in a box that's been opened. Tomorrow will tell.

 

The closest match fuel pump was from the 1979 4.9L I6. The 1980 pump was about 1/2 inch shorter than the pump I removed from the tuck. I used the 1979 pump.

I also did a full oil change with another new filter.

This was a precaution just in case fuel leaked from the fuel pump into the oil.

 

Here is a couple of pics of my 1980 f100 manifold if it helps? but this is a manual truck they may be a bit different

 

Here is the pump that is in my truck

 

Mike - Well, now you know. But I wouldn't have guessed that.