Smog equipment removal on 87 TBI
 

I want to pull the smog stuff off of my 87 Jimmy (350 TBI/ 700R4 Trans).

What can go?
What has to stay?
Will I see any improvements other than it will look cleaner under the hood? What is the plug size for the 2 holes in the manifolds?

Thanks!

Rob

Re: Smog equipment removal on 87 TBI
 

I don’t think you’ll notice a gain buddy. Those TBI motors aren’t power makers. If you do remove it all though, I think the plug size is the same size as a drain plug for a Cummins 5.9 oil pan. I’m pretty sure. Been awhile since I played with those manifolds.

Re: Smog equipment removal on 87 TBI
 

Thanks for the info. Do you know what year of Cummins? I went to OReillys and we pulled up a couple of drain plugs, but they were the wrong thread pitch M22 - 1.5. Apparently, the thread pitch of the smog holes are M22 1.25. Appreciate the help and love your "summer" Burb!

Re: Smog equipment removal on 87 TBI
 

I get those type of plugs at Home Depot.

Re: Smog equipment removal on 87 TBI
 

HD carries M22 1.25?

Re: Smog equipment removal on 87 TBI
 

Update: I was wrong about the thread pitch, it is M22 1.5 not 1.25. I grabbed 2 oil drain plugs for a diesel at the parts store and they fit perfect, :metal:. For future questions on this matter, the part number is Dorman 652886.

ALSO, if anyone wants this smog equipment, I will gladly box it up and send it to you if you pay shipping, just let me know :metal:.