1983 F100 CA Emissions or 49 State?

I need to replace my engine in my 83 F100 with the 5.0. I was planning on getting a remanufactured long block to save time instead of doing it myself with machine shop time etc. If I look at Napa or Autozone for example, it mentions that my truck has smog on the back of the heads. I looked and didnt see anything on the back of the heads. Was there a CA emissions and a 49 state emissions in 1983? This truck was bought new in Arkansas and I want to make sure I get the right engine and can pass smog next year.

Hey Bisquick,

They are referring to the Thermactor ports on the back of the cylinder heads. See below picture of my 1984 5.0 as it was originally. There is a tube that runs across the back of the engine and attaches to each cylinder head just above the frost plugs. As far as I know, all small block Ford heads from about 1978-1996 should have these ports (somebody can correct me if I'm wrong). I have a set of late 90's GT40 heads on my 5.0 now, and they do NOT have these ports, but most heads will AFAIK.

Mine doesn't have anything there. I just have a tube going to the passenger side manifold from the smog pump. Will I be able to block off those ports or are they all listing the wrong engine?

Bisquik1959 wrote

Mine doesn't have anything there. I just have a tube going to the passenger side manifold from the smog pump. Will I be able to block off those ports or are they all listing the wrong engine?

You can buy plugs for them just Google thermactor port plugs I know places like Jegs and Summit sell them. I believe they are 5/8” so some people just use bolts to plug them.

5/8-11 x 1/2" or so for Windsors.
Use a crush washer under the head of the bolt.

Every V-8 truck engine of this era should have come with a thermactor crossover, check valve then plumbed to the A.I.R. pump with a bypass valve.

Here's what they are talking about.  This is from our page at Documentation/Emissions/Thermactor Systems.

Yep!

 So you see 9B449 (the thermactor tube) 9A487 (the check valve) and 9B289 (the bypass valve) coming from the pump.

I didn't realize something as early as an '83 would have another tube for preheating the catalytic converter.

I know my non-catalyst heavy duty vehicle used air injection to burn off some of the HC and CO without resorting to a cat. But that doesn't hold true for vehicles under #8,500.

Here's a plug kit fyi:

https://www.jegs.com/shop/m20ProductDisplayView?catalogId=10001&langId=-1&productId=1681664&storeId=10001&pgGrp=catNav

As mentioned though you can just use bolts, many have.

Hmmm.... those diagrams dont match what I have. Nothing on the back of the heads and just a hose from the smog pump to the passenger side exhaust manifold. Looks like I will get the new engine and block these off.

What's the chance you have a carb swapped EFI engine in your truck?

Because that's what it seems like from here.

The truck was bought new by a family member and supposed to be all original. I don't see any receipts or anything showing a motor swap/rebuild or anything. Unfortunately, nobody is around to ask anymore.

The smog guy doesn't take any exceptions to it when its smogged. Just want to make sure I am getting the right replacement engine for it. It has terrible crank case pressure and leaks out of every gasket for the most part.