Removing Smog on a 81 305

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1987 GMC Jimmy

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Smog and air injection are different names for the same thing. You’re keeping the TCC lockup switch. I’d probably say to hell with the distributor delay since the EFE TVS is gone.

Wait, why are you getting rid of the A/C? That compressor’s seals are 100% likely to be shot from sitting so long, but it wouldn’t take very much to get the system up and running either with a new production R4 (pancake) unit or a Sanden conversion. I avoid getting into a vehicle with A/C unless I’m in a bind, but I live in palm tree country. Does that make me another way to call a cat or kitten? Maybe. But at least I can ponder that with sub-freezing air blowing on me when it’s 105* outside. If you live up north, that might be a different story.

Oh, and I’ve used Delco reman brake boosters on GM and Ford products with good results. I used RockAuto, but check around, and make sure any core fee doesn’t kill the deal after shipping and taxes.
 
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Gideon
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1981
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5.0 305 4BBL
You're in the USA, which state only you know. Any smog stuff you remove, keep it. You may need it later. Don't toss it.
I am in the great state of Ohio, we don't test where I live and I plan on swapping the engine at some time. But you have a great point. Will keep the stuff so I can put it back together in case someone needs it on their 305 or if a strict emissions state buyer wants the whole thing.

but I digress. We are supposed to get some cold weather this weekend so all my plans are scrapped as I do not have a garage to work in.

I will keep coming back with updates and lots and lots of questions.

To plug where I remove stuff, is there a kit I should get? or just vacuum stuff in general?
 
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Smog and air injection are different names for the same thing. You’re keeping the TCC lockup switch. I’d probably say to hell with the distributor delay since the EFE TVS is gone.

Wait, why are you getting rid of the A/C? That compressor’s seals are 100% likely to be shot from sitting so long, but it wouldn’t take very much to get the system up and running either with a new production R4 (pancake) unit or a Sanden conversion. I avoid getting into a vehicle with A/C unless I’m in a bind, but I live in palm tree country. Does that make me another way to call a cat or kitten? Maybe. But at least I can ponder that with sub-freezing air blowing on me when it’s 105* outside. If you live up north, that might be a different story.

Oh, and I’ve used Delco reman brake boosters on GM and Ford products with good results. I used RockAuto, but check around, and make sure any core fee doesn’t kill the deal after shipping and taxes.

Yeah I live up in Ohio but the summer can be unbearable. I was just listing what I was gathering so far. I would prefer to keep A/C cause that is something I like but if it makes things easier or better in the long run I am up for anything.

Thanks for the recommendation on boosters!

Hoping to buy a lot of parts and then spend a weekend putting them all on. this Smog removal seems the biggest job I have to do next to the brake booster. it is interesting learning about all these things that make the whole Truck work.
 

Octane

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Additional info so you don't have to ask.
Truck sat for a long time, no idea how long unfortunately.
I am aware of my Brake Booster leaking real bad. working on finding a new one.

I am new to this whole thing but this truck has a lot of sentimental value so I want to fix it up and make it real nice again.

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If you have brake fluid leaking thru to the brake booster you can buy a combo unit mastercylinder with booster included for cheaper than the two parts separately
 

HotRodPC

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I'd leave the EVAP Canister. I don't see how that affects HP at all. I'd just leave that. And there shouldn't be Cats to worry about. I'd just remove the AIR system and pump since you're going to headers and cap off the EGR.
 
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I didn't disappear! Just waiting for a break in the cold to get started on the Smog removal. will post pictures of progress and things I take off so stay tuned I guess if you want to see it.
 

BillWill

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I know I saw a post somewhere (thought for sure it was in this forum) that showed pictures of before/after vacuum hoses for removing the smog stuff. If anyone else can find and post I'm sure it will be helpful as I just can't seem to find it. I ran into many of the same issues when I got my 86 K10 and since the smog pump was already gone and most of my hoses were plugged with nails and hot glue I never worried about it.
I made the mistake recently of trying to look into my radiator leaking and both my evap can and connector hoses literally collapsed and crumbled when I went to move them.
 

Hugeroost

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Was not aware they ever put a 305 in a 3/4T truck, wtf were they thinking. Are we sure its not a 350, I mean a damm 05 would barely pull the truck alone much less w a trailer or a load in back. If in fact a 05 i'd throw it away as fast as I could before I spent money on it
 

Hugeroost

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Hopefully he's in Texas, and why get rid of the AC, i'd get that back up and goin if it were me, I'll take the trade off
 

Shorty81

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Welcome Gideon, I'm from Ohio too. I don't have ac and don't want it. I have rear slider window, and with side Windows and wings open and kick panel vents open I stay plenty cool. I'm just South of Lima.
 
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Was not aware they ever put a 305 in a 3/4T truck, wtf were they thinking. Are we sure its not a 350, I mean a damm 05 would barely pull the truck alone much less w a trailer or a load in back. If in fact a 05 i'd throw it away as fast as I could before I spent money on it

Next Post will be my I think they are called RPO codes picture, from the glovebox.

Hopefully he's in Texas, and why get rid of the AC, i'd get that back up and goin if it were me, I'll take the trade off

Nope Ohio! Gets humid enough for me to want to keep it.

Welcome Gideon, I'm from Ohio too. I don't have ac and don't want it. I have rear slider window, and with side Windows and wings open and kick panel vents open I stay plenty cool. I'm just South of Lima.

Thanks! oh I am just North of Dayton. I have a solid rear window. I will start a thread this week weather and work permitting of my truck with pictures


As far as the Smog removal, I have been dead in the water between work and weather. I have a bunch of little stuff to do to the Truck while I wait for a window to install everything.
 
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As far as I know I am the 2nd owner and that nothing other than regular maintenance was done. I am under the impression most of the truck is Stock.

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82Diesel

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If you plan to remove A/C and brackets I know they are really tough to find for teh 305/350 engs and easily could get a couple hundred !!! I see them all the time for bbcs since so many camper specials came with A/C Standard Vs SBC. IMO
 

FireTruck1984

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I need a Tetanus shot after looking at those photos! :)
 

Arkansas_V8

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A yankee talking about humidity. I needed that laugh. Thanks.
 

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