Emmisions stuff
 

I was looking at my donor '87 lwb with 305 and noticed it doesn't have a smog pump or anything else going to the exhaust manifolds. Seems like a headers would be a breeze here.
I was also looking at my '86 GMC 4x4 with 305 and a friends '87 swb with a 350 and they both have smog pumps that attach to the exhaust manifolds.
I looked as close as I could at my '87 and it didn't look like there was ever a smog pump installed, but who knows 18 years later?
The sticker on my core support says: CATALYST, BPERG/ORC (I think). Does this say there is no smog pump?
Just curious as I don't really want to hassle with the pump if I don't have to.

It does not have one because it was never made wih one, you dont need it on that truck.

Why exactly do you say that? '87 swd with 305 not required to have a smog pump? Or ?

From what your sticker on your core support says it didnt have one from the factory, like mine, and you will not need it to pass an emmisions test.

PS- its not required to have one because it was made without one. 87 LWB didnt have them but the 4X4s did and some SWB did.

my '81 was a original 305 and it has one. I think it shows one on the sticker though.

Sounds odd, but I guess I have the proof in front of me to prove that out?

I thought all of them had all that stuff since 73? My 81 had a 4.1L in it with all that stuff on it. Pump and everything.

Ill find all my info on this and post it. Some didnt have it and some did, my uncles 79 short bed doesnt have the pump or anything.

My 82 had a 305 stock it didnt have one.

I went by my dads house to get a look at my '86 GMC that has the smog pump. It says "AIR" on the sticker so I assume that is for the air (smog?) pump.