New project '86 GMC K1500 SWB - Few questions

[jhama78]

Posting up a few pics of my latest acquisition, 86 GMC SWB 4wd. Bought it from the 2nd owner who drove it to the east coast from Colorado. Started life as a 305 truck and its had a 350 gm crate engine swapped in as well as a rebuilt 700R4 installed last year. The truck runs and drives well for its age but like anything thats 29 years old with 150K miles it needs a little bit of work.

My immediate plans are to get a new muffler and tailpipe on it and check out the necessary stuff that it needs to pass Va inspection - lights, wipers, brakes, etc. Also I plan on cleaning up (i.e. ditching) a bunch of the vac lines on the smog stuff since they are falling apart and I dont want to have to deal with vacuum leaks. And before the emissions police pipe up, I dont have to worry about that on a vehicle this old in the area that I live.

Also the stock electric quadrajet is in need of a rebuild/cleaning, so I will most likely buy a reman carb from summit, jegs, etc without the electronics to replace it. While I am at it I plan on swapping out the ESC controlled distributor with a standard late 70s era HEI in order to simplify that as well.

Any tips/pointers that you all can provide so far as desmogging/converting the carb and distributor over to pre-80s configuration would be welcomed.

Here are a few pics of the truck as I got it, I will post another set of pics along with a few more questions below.

SPID

[jhama78]

So far I swapped out the valve cover gaskets that were leaking like a sieve and replaced a few bulbs that were burnt out. I'd like to choke the person that decided to mount the EGR valve on top of the passenger side valve cover btw. I'm debating make a block off plate for that as well when I do the carb/distributor work. Opinions?

Onto my next couple of questions:

While I was changing the passenger side valve cover I found this wire laying behind the engine:



Any idea what it goes to? It looks like it has an HEI plug with a fusible link on it but the truck runs fine now and looks to have all of the correct wires in the right place.

Also the A/C Heat box doesnt look like a factory install as well... Maybe a dealer installed a/c? The truck originally came from Montana so maybe it was shipped without A/C and then dealer converted?

???


Tag on top of box


Compressor


Nice fix on the a/c line



I'd at some point in the future get the A/C working again, the P/O said that it worked fine until he installed the engine and the refrigerant evidently leaked out of the awesome fix with hose clamps when he took the compressor off of the engine during the swap. One other thing the P/O told me was that he had to replace the blower motor and the application that came up for it was one for a Van and not an 86 GMC, anybody heard of this?

Anyhoo thanks for any and all advice, looking forward to working on this thing... theres a huge difference under the hood when compared to the 77 K20 I used to have so far as extra stuff bolted to the engine.

[jhama78]

Right now I am looking at something along these lines for a replacement carb:

http://www.summitracing.com/parts/sum-210216

or

http://www.jegs.com/i/JEGS-Performan...15805/10001/-1

I know I could get another intake and bolt up a holley 600 or replace the quadrajet with an edelbrock but I'm not really looking to get that deep into this thing right now. I'm more interested in simplicity and retaining the factory geometry of the TV cable, Cruise control (that works great BTW) and the stock throttle linkage.

The distributor I am looking at is something like this since it need wires anyway:

http://www.jegs.com/i/JEGS-Performan...0002K/10002/-1

What kind of initial and total timing would be correct in this application? 12-14° initial and @ 32-34° total? Should I worry with vac advance or just cap it off and let the mechanical adv do its thing?

The last SBC distributor I messed with was on a 383 in my mud truck (10 years ago) that was locked out at 36° so I dont have too much experience with vac/mech advance.

Thanks again for your replies, I am sure that I'll have a hundred more questions once I get into working on this thing.

[johnwaynejeep]

Good lookin truck.

I've seen this done improperly on a mid 80s wagoner and it was terrible. Loose vacuum lines, open CTO valves, disconnected EGR.

I would suggest having a plan before you start so you know where you plan to end up and keep in mind you'll have to readjust your carb after words because of all the changes.

As far as the loose wire goes. I've noticed GM is very good about using keyed connections that only go in one place. It should be easy enough to look for the male connection it goes to or trace it back to the fuse panel and identify which system it works with.

Good luck.

[beamn7]

Nice truck! High Altitude emissions option and LE9 305 engine means you don't have the electronic quadrajet. It will have a plug on the top of it but all that does is cut the accelerator pump flow in half once the engine is warmed up. Other than that, it operates as a standard quadrajet. You can simply unplug that if you want. The single wire plug on the pass side of the carb is for the choke. The electronic ones that actually used a mixture control solenoid also had a 3 wire plug on the drivers side front of the carb for a throttle position sensor in addition to the plug on the top. Majority of those were CA emissions. So.........a simple overhaul of the carb may do you wonders for both drivability and your pocket book.

[Robert8096]

Originally Posted by jhama78

Right now I am looking at something along these lines for a replacement carb:

http://www.summitracing.com/parts/sum-210216

or

http://www.jegs.com/i/JEGS-Performan...15805/10001/-1

I know I could get another intake and bolt up a holley 600 or replace the quadrajet with an edelbrock but I'm not really looking to get that deep into this thing right now. I'm more interested in simplicity and retaining the factory geometry of the TV cable, Cruise control (that works great BTW) and the stock throttle linkage.



The distributor I am looking at is something like this since it need wires anyway:

http://www.jegs.com/i/JEGS-Performan...0002K/10002/-1

What kind of initial and total timing would be correct in this application? 12-14° initial and @ 32-34° total? Should I worry with vac advance or just cap it off and let the mechanical adv do its thing?

The last SBC distributor I messed with was on a 383 in my mud truck (10 years ago) that was locked out at 36° so I dont have too much experience with vac/mech advance.

Thanks again for your replies, I am sure that I'll have a hundred more questions once I get into working on this thing.

Check this guy out for a quadajet carb. They are far more superior than one from of those links. You can call him and give him your specs and he will build you one to match. The only downside is it takes a few weeks to get.

Sean Murphy Induction
http://www.smicarburetor.com/products/sfID1/28/sfID2/9

[jhama78]

Originally Posted by johnwaynejeep

Good lookin truck.

I've seen this done improperly on a mid 80s wagoner and it was terrible. Loose vacuum lines, open CTO valves, disconnected EGR.

I would suggest having a plan before you start so you know where you plan to end up and keep in mind you'll have to readjust your carb after words because of all the changes.

As far as the loose wire goes. I've noticed GM is very good about using keyed connections that only go in one place. It should be easy enough to look for the male connection it goes to or trace it back to the fuse panel and identify which system it works with.

Good luck.

Thanks for the input, I dont plan on going at this project WFO like some crazed teenager and just yanking everything off without thinking about it.

My plan is to swap out the carb and distributor and only keep what is needed to run the engine so far as vac lines, all the while neatening up the clusterfawk of excess stuff on the engine.

Originally Posted by beamn7

Nice truck! High Altitude emissions option and LE9 305 engine means you don't have the electronic quadrajet. It will have a plug on the top of it but all that does is cut the accelerator pump flow in half once the engine is warmed up. Other than that, it operates as a standard quadrajet. You can simply unplug that if you want. The single wire plug on the pass side of the carb is for the choke. The electronic ones that actually used a mixture control solenoid also had a 3 wire plug on the drivers side front of the carb for a throttle position sensor in addition to the plug on the top. Majority of those were CA emissions. So.........a simple overhaul of the carb may do you wonders for both drivability and your pocket book.

I had forgotten that there was a 3rd version of the quadrajet on these trucks for Cali Emissions...

So, what I refer to as an electronic quadrajet on the east coast of Va and what you refer to as one out in Ca are obviously different...

I definitely dont have the mixture solenoid or TPS on mine and was just going to simplify it even more when I replace it with an older version with the only electronics being the connection for a choke heater.

Thanks for the info

[jhama78]

Originally Posted by Robert8096

Check this guy out for a quadajet carb. They are far more superior than one from of those links. You can call him and give him your specs and he will build you one to match. The only downside is it takes a few weeks to get.

Sean Murphy Induction
http://www.smicarburetor.com/products/sfID1/28/sfID2/9

I actually read a few threads referencing his rebuilds last night. I'll have to give him a shout.

Thanks for the info.

[jhama78]

When I bought the truck the previous owner mentioned something about having an Accel Distributor, Coil, and Wires from a previous project that he used for a short time and then removed when he parted it out. I showed up at work today and these parts were sitting on my desk in slightly used but excellent condition.



That being said, anybody have some insight into the adjustment of the vacuum advance versus mechanical? I read the instructions for the distributor and it sounds fairly cut and dry but having never done this before I am looking for some opinions on it. Or should I just plug the vaccum port and run solely on mechanical advance?

thanks for the insight gents.

[jhama78]

:crickets:

Would it be better for me to post my questions about the carb and distributor in the engine forum versus in here?

[jhama78]

Going to tackle the distributor swap next week. Bumping this up top for insight on the vac/mechanical advance.

thanks for any input.

[jhama78]

Quick update to this pile:

Haven't gotten around to the distributor swap as of yet and the carb has seemed to clear up a little bit after driving the truck some. Its still on the short list of things to do but brakes, bearings, and gear oil changes have taken priority. Swapped out the rear brakes, axle bearings, seals, and gear oil a few weeks ago without too much heartache. The center pin retaining bolt did break but luckily there was only 1 thread holding it in the carrier and I was able to get it out with a pick.



The gear oil was hideous but thats to be expected from a vehicle that sat as much as this one did prior to my buying it.



The only other thing that was odd is the passenger side axle shaft had a 'splinter' of what looks like the hardening on the shaft coming off of it. here are a few pics:





Anybody ever seen anything like this? I didn't have an option of a replacement shaft so it got reinstalled minus the match stick sized flake of steel. I'm honestly not too worried about the axle breaking with the bone stock 350 in the truck so its most likely fine.

[jhama78]

This past weekend I installed new bearings, seals and brakes on the front axle, as well as changed out the gear oil which looked waaay better than the rear. Everybody has seen pics of caliper and bearing swaps before but I will post a couple of pics of the bearing, race, seal, caliper and pad part numbers in case they may help somebody in the future. Ive got new brake hoses in hand to swap out this weekend since the stockers are 30 years old now.

I bought 3 grease seals since I normally mess one up on installation so thats why there are an odd number of boxes in the pic.



and lastly the semi loaded calipers and acdelco pads

[1redbowtie3]

I've started on my 85 K20, it's at the body shop now, and I'm doing the same in a couple weeks ... going through the drivetrain and replacing seals and bearings. I'll be looking forward to tips!

[1redbowtie3]

Originally Posted by jhama78

What kind of initial and total timing would be correct in this application? 12-14° initial and @ 32-34° total? Should I worry with vac advance or just cap it off and let the mechanical adv do its thing?

The vacuum advance is needed, it's for part throttle driving ... connect it to the 'ported vacuum' side of your carb, if I remember it's the drivers side ..

[jhama78]

Just got off of the phone with Sean at SMI and have a Stage 1 750cfm Quadrajet on the way.

http://www.smicarburetor.com/product...2/productID/18

Just in case anybody else is wondering, the lead time on them is 7-8 weeks. Im looking forward to getting this thing running well and actually having a choke that works as it should.

[D13]

love the truck!

that AC is definitely not factory.

[jhama78]

Originally Posted by D13

love the truck!

that AC is definitely not factory.

Thanks and yeah the a/c doesnt look like anything else ive ever seen installed in this style truck. Right now Im on the search for a blower motor resistor and am coming up empty. Only thing that looks close is one for a G series van but even that one doesnt have the correct number of terminals. I may order one off of amazon to see if it will work and if not send it back for free.

[jhama78]

Finally got around to swapping out the brake hoses this past weekend. This job also gave me a reason to buy the Motive Power Bleeder that I've wanted forever.



Here are the Dorman part numbers for all three brake hoses as well as the AC Delco p/n for the copper crush washers for the banjo bolts.



One trick I use to check for leaks is to put a shop towel under each connection once I hose the area off with brake parts cleaner and make sure its dry. I then pressurize the system and drink a beer while checking for drips to hit the towels.



I should note that before I started the bleeding process I used a turkey baster to suck out the old brake fluid from the master cylinder and wiped the inside clean before I poured in new fluid. The Motive power bleeder makes quick work of the bleeding process and doesnt drink near as much beer as my previous brake bleeding assistants have in the past... The brakes feel great and the truck stops much better than it did before.

[jhama78]

Originally Posted by jhama78

Just got off of the phone with Sean at SMI and have a Stage 1 750cfm Quadrajet on the way.

http://www.smicarburetor.com/product...2/productID/18

Just in case anybody else is wondering, the lead time on them is 7-8 weeks. Im looking forward to getting this thing running well and actually having a choke that works as it should.

Contacted Sean yesterday and my carb ships out this week. Cant wait to have a new carb and a choke that works correctly. Install pics to follow.

[jhama78]

Quick update to this thread, just now getting around to working on the truck. Been a busy year and a half at work with travel. I've been gone 177 days this year so fitting in truck work around family time has almost been impossible. Luckily I have one short trip left this year and then will be home for about 2.5 months. Truck is still running ok, but will be much better with the new carb, distributor and tune up parts. Also picked up a set of door pins and bushings, ebrake cables and weather stripping for the doors/windows. Updates to follow.