Hello! First time square body owner here!

[Bman]

Hi everyone. Ill start off saying Im New and first time square body owner, first GM vehicle for that matter. My names Ben, but growing up i was called Bman so it stuck. hence the Name. Im 18 just getting ready for college. Im decent with mechanics and electronics. i grew up doing it all the time.

Now for the Truck. Well it started off as i got my first truck. It was a 1976 F100 Custom. 302. 4speed bulldog LWB I put quite a bit of work into that ole truck, Did everything short of pulling the engine as far as tune up. It had its problems though. Manual steering and brakes. brakes only half there. no ac or heat. it was nothing but a beast to drive. i got used to it though. first manual i ever drove. I had done all the work to that truck to get it ready for the road.

Then one day i got an email of a guy wanting to trade me for the 83' GMC. told me it had heat. power everything and at first i was told it was a 350/350.

Well i figured thats too nice sounding for a straight trade. so i dismissed it. then he emailed me again so i said alright lets meet up. we ended up trading and there i got the GMC.

as expected it had its problems. some small rust and the rad looked horrible. held in by hangers and no shroud. and its choke doesnt work so it has to warm up awhile to get going. but it was automatic and power everything. so i traded to make my dad happy because its a safer truck.

Went to Pull-a-part and got me a shroud. had a rad already and fixed that all up. the engine had a bad emissions delete job done to it. so i tided that up a bit. put new valve cover gaskets and painted the covers to look good.

installed a temp gauge and some lights. (the trucks oil pressure gauge is stuck at 60lbs and the temp isnt hooked up anymore.) It runs real smooth. and strong. shifts like a dream. it runs about 20lbs pressure at idle and goes up to 40lbs when your driving. im not sure if thats right. but i was told its okay pressure.

Then i found out its not a 350. its a 305 LE9. still. one of the better 305s. and the trans is actually a Turbo 400 so im pleased with that for sure. did some research and found they came out of a g20 3/4ton van. the only thing is the guy said it had a shift kit. and well depending on how i "fix" the vacuum lines it acts like it does( longer gears. firmer shifts etc). but if i just leave the lines alone and dont try to seal all the leaks it shifts normally. a firm but smooth shift and it does every gear just perfect.

the truck had dual tanks orginally. but had its passenger tank took out and the bed had a new piece of sheet put in to patch where the filler had been.

I painted the patch and other spots to seal up the rust. I painted the entire inside of the bed and got a bed box and mat. threw on some lights and here i am now!

So far. I love the ole square body. GMC sierra classic. and ive become a GM guy. toughest thing i ever drove.


Here some pics to go with the story!

 

[tiredtiretodd]

It was worth the trade, that's a good looking truck.

 

[dhamp]

You most definitely came out on top of that trade! Welcome!

 

[Bman]

Yeah its been a great truck. things i need to still fix are. Transcooler. all it has is a external cooler and not hooked to the one in the rad.

A head light needs replaced. The rear main leaks. and fix the choke.

 

[marks86]

nice truck man
welcome to the club
please get rid of those god damn hub cabs

 

[Bman]

I plan to! gotta get some nice wheels

 

[MadOgre]

Yep definitely better ride your in now ! Cause I hate Fords lol.

Post up some pics of your choke maybe we can get that sorted out for you.

 

[Bman]

I will tomorrow. its a quadrajet 4bbl electric choke. also i found what apears to be a ecm or pcm? tucked up under the passenger dash. straight above the glove box. (had it out looking at the heat core set up. needs a new one) but why would it have a computer? if thats what it is.

Also. how do i know if this emissions delete is done okay? the only things left hooked up (rest are plugged) are the vacum advance. the choke-pull off. and the PCV. rest are plugged off. its a Rochester model M4ME. and the electric hook up on the front of the carb is not hooked up.

One things. truck runs pretty rich. im not sure how to adjust that. and im not sure the secondaries are opening?

 

[Bman]

here are some pics

 

[Bman]

i believe this is a thermal controlled vacuum ports? if so should i plug these off or do i need these hooked up somewhere?

 

[Bman]

To elaborate on the shifting be effected by vacuum. so i know right now( how i normally drive it) it has vacums leaks. open ports, old pugged lines, etc. and it shifts good. smooth and firm and i think at about the right time. 1st shifts about 15mph then 2nd is about 40mph. then its third.

If i go through and re-plug the ports good and basicly make sure theres no leaks. itll shift into gear much firmer almost hard. then first gear will hold all the way up to 35-40mph and the shift will be very firm. then it holds the 2gear up to about 50-55mph and really firm shift again.

the guy said it had a shift kit in it. but could that be it? or does the modulator need adjusted? if so. how do you do it?

 

[MadOgre]

i believe this is a thermal controlled vacuum ports? if so should i plug these off or do i need these hooked up somewhere?

Nope it looks like you have your vacuum advance on the distributor hooked up to manifold vacuum from the carb. Mine has a solid plug where your temp port is. Its just a temperature actuated switch. so vacuum in one side and out the other depending on whether or not your engine was warm or not.

Do you have 12 volts to the choke with the ignition on?

 

[MadOgre]

Other question. Do you still have the black plastic cylinder canister on the drivers side beside the rad ?

Guys for some reason seem to think that they need to disconnect this for some reason when they remove the pollution crap.

It is really just a way to recycle fuel tank vapor back to the carburetor to improve fuel efficiency and air pollution. It does not impede performance one bit.

 

[MadOgre]

That is a beauty of a carb. Exactly what most of us are looking for when we go carb hunting. Looks like it could stand having an over haul though.

EDIT: OH I missed that electronic port on the carb. I take my words back. You would be wise to try and find a carb at the wreckers that is excactly like yours but with out the electronic port.

Like this :

You must be registered for see images attach

Also im guessing there is an electronic port coming out of your distributor below the rotor cap ?

 

[Bman]

Yeah ive still got it. and does that mean the vacuum advance is right or wrong?