changing out the alternator in my '74 CA Bronco with smog equipment

[tommyg]

my '74 needs a new alternator, and still has all it's original smog stuff on. Sure would be easier to change out the alternator without the thermactor system on the truck. More trouble than it's worth, should I just keep it as is? Appreciate any feedback from those who have done it. I bought a 2 pulley alternator, but am now thinking whether it's better to work through pulling the smog stuff.

'74 will never need to be smogged in CA fwiw.

 

[sykanr0ng]

My opinion?
I would remove it, unless you think you should keep it all original.
The primitive smog devices of the late 60s and early 70s were not very good and more trouble than they are worth.

 

[tommyg]

definitely agree. Only question --- anything I have to be careful of in removing smog equipment? i.e. am my going to run into more hassles trying to take it off versus just leaving it on?

 

[thegreatjustino]

I don't know how the '74 differs from my '67, but the heads on my '67 have ports that tie into the thermactor system. If I remove the air pump and related hoses going to all the ports on the system, it leaves two big holes in the heads that backfire. The plugs that I've found so far look nothing like what I'd need to plug these holes.

Thus far I've just removed the belt from the smog pump and left everything in place. Time will tell what my ultimate decision regarding the smog system will be.

 

[sykanr0ng]

I don't know how the '74 differs from my '67, but the heads on my '67 have ports that tie into the thermactor system. If I remove the air pump and related hoses going to all the ports on the system, it leaves two big holes in the heads that backfire. The plugs that I've found so far look nothing like what I'd need to plug these holes.

Thus far I've just removed the belt from the smog pump and left everything in place. Time will tell what my ultimate decision regarding the smog system will be.

The standard size for those holes is a 5/8-11 NC thread.
Many times they are full of carbon.

 

[73azbronco]

If it runs fine leave it be. I had a 66 6cyl from CA with the smog pump, a 66 six cylinder! Ran fine, I left it alone.

 

[Rustytruck]

'74 will never need to be smogged in CA fwiw.

Living in this corrupt state I would never bet a dollar on this statement but if you take the stuff off take pictures and put the parts in a labeled box and store it away for a later day.

Changing out the alternator is the same work as replacing all the smog parts. You will have to get the old style alternator mount and slotted alternator bracket. You will also need to make a spacer between the alternator and the engine block to line up with the 1974 pullys and its special waterpump for the smog pump motor.

 

[sykanr0ng]

How the air pump really works is to pump outside fresh air into the exhaust to dilute the gasses so the vehicle will pass emissions, it does not remove any pollution or cause the engine to make less pollution.

 

[tommyg]

Living in this corrupt state I would never bet a dollar on this statement but if you take the stuff off take pictures and put the parts in a labeled box and store it away for a later day.

Changing out the alternator is the same work as replacing all the smog parts. You will have to get the old style alternator mount and slotted alternator bracket. You will also need to make a spacer between the alternator and the engine block to line up with the 1974 pullys and its special waterpump for the smog pump motor.

I bought a new alternator at O'Reilly's --- they had two versions, one for one pulley (no smog), one with two pulleys (with smog). I assumed the two pulley version would be plug and play, sounds as though that's not the case?

 

[Rustytruck]

It would be plug and play if you keep the factory cast iron bracket and the water pump pulleys and water pump. The cast iron bracket, water pump and pulleys are a set. The 1974 smog pump water pump is 3/16" longer than the standard 289/302 water pump. if you change to the early alternator mount you need to align the alternator to your old pulleys. The alternator is the same with either the one groove pulley or the 2 groove pulley.
Not too long ago when you bought the alternator they all came with 1 groove pulley and you had to swap the 2 groove pulley on.
I am surprised they have a 2 groove alternator in stock.

 

[tommyg]

It would be plug and play if you keep the factory cast iron bracket and the water pump pulleys and water pump. The cast iron bracket, water pump and pulleys are a set. The 1974 smog pump water pump is 3/16" longer than the standard 289/302 water pump. if you change to the early alternator mount you need to align the alternator to your old pulleys. The alternator is the same with either the one groove pulley or the 2 groove pulley.
Not too long ago when you bought the alternator they all came with 1 groove pulley and you had to swap the 2 groove pulley on.
I am surprised they have a 2 groove alternator in stock.

Got it, thanks. Think I'm just going to keep the smog stuff in there for now and swap in the new alternator as-is.