Hello

I had my carb open to clean it and noticed both jets appear to be the same size and have 64 stamped on them.

However, the service sheet says the jets are different sizes (63 and 65) and that the lean jet should be on the choke side of the bowl and the richer jet on the pump side.

This truck has ran alright up until recently hence why I went through the carb... again.

but, when it does run it does have some quirks like having to run with the choke partially on for a short time after the motor is warm to prevent hesitation on acceleration from dead stop. (mainly cool mornings and winter). This isn't a big deal since I have a manual choke but, it is a little annoying since I know it shouldn't be doing it. Whether or not the jets are the problem I don't know.

But, I am curious are the jets and numbers stamped on them universal or do they only work with this model carb?

 

Is there some kind of resource like a book or chart that shows what the correct jet sizing by engine application? In my case a stock 5.9L 360 with A/T.

The service sheet has a "Adjustment Data Table" for Chrysler and IH Products but, that table doesn't mentions jetting so that must everything in the table must use the 63 and 65 jets?

Here is a PDF so you can see what I mean:
http://documents.holley.com/3-711instructions.pdf

 

The problem your having is that the carb is too lean to want to run on todays fuels.
It's a tuning nightmare all on its own...

 

Alright, I see.

So, am I hurting the engine by driving it that way? Lean would mean higher operating temps?

When I have time, I plan on doing a gm hei retrofit and regap my plugs to .045". Would the hotter spark compensate for the lean condition?

If not, I came a cross a site that list replacement jets for the 2245 but, only in one size which is #100. Assume the numbering system is the same thats quite a step up (Also assuming the larger the number the richer the mixture, I know nothing about this level of tuning). Would that richen the carb or is it's lean nature engineered into the whole thing?

Failing that a different carb...

 

Only true way find out is to measure it.... Tail Pipe sniffer or a wide band 02..
The other ways are just a crap shoot.

 

Alright, I get it. I can do it the old school way which is basically trial and error. I might even stop the stumble but, the air/fuel ratio still may not be right, correct?

I ran a cross a youtube video about a year ago by Mighty Car Mods that talked about those 02 sensors kits. they looked pretty neat

They look a little pricey depending on which one you get. Is there one you could recommend that would fit my needs? Which is tuning an old stock work truck for reliably and economy, I've yet to tow anything.

On a side note:

So, all these old stock carburetors are set up for fuels that no longer exist? My other truck with a 318 has the Carter BBD that I've had for 3 years now. (wow can't believe it's been that long) I think it runs pretty darn good and I've never touched it really. It's an older reman. and I know people hate this carburetor too but, it's been good to me but, it's amazing that carbureted engines don't have more problems than they do since the fuels are different.