I just joined today, I have a 77 gmc jimmy with a 400. I live in California and my gmc has no smog equipment on it. I was hoping if anyone knew what smog parts needed to be put back on it. I read that it didn't need a cat or egr valve on it. Then some say it needs a pump, cat, diverter valve and a egr. I just want to be sure before I go and buy all the wrong parts. thanks

 

Call or go to the smog referee. They are the only ones who can tell you straight!

Not sure but I don't think that a 77 needs to be smoged, I think it only goes back to 78. I know 79 needs it cuz I have a 79 Toyota 4by I wanted to get fancy with and can't.

 

I agree. I know that my '74 doesn't have any of that stuff on there, however, things changed somewhere in the '75-'76 time frame in terms of emissions regulations and how they relate to higher GVWR vehicles. With CA being on the fore-front of emissions regulations, your truck likely had a lot of emissions stuff on it.

 

Thanks for the advise, I think I will go and see what the ref say's. thanks