Sullii the 72 GMC 1500

[regan wilson]

Looks really cool and sits good.

[cornerstone]

Looks really good. I'll be interested to see the way you handle relocating the fuel filler neck and the results of your charcoal cannister / vent set-up. I know it'll be well done that's for sure.

[hewittca]

Thank you guys! My solution for the fuel filler is dependent on the 5" bed floor raise that I did. I actually didn't even plan ahead for that, but after putting a bed side on and realizing the floor is now above the marker light, I thought I must utilize that to add the fuel filler behind the marker light. I will detail it once I get it fully installed. My only concern with it is that my filler tube will be close to horizontal going into a 90 degree neck on the tank. Hopefully it isn't slow to fill. I'll find out soon enough. Most of the things I've done on this truck are the result of experiment, not experience!

As for the vent line, I think it is working so far. I have the tank full of gas and the truck has just been sitting in the garage in this 100 degree heat. So far, not even a hint of gas that I can smell.

[hewittca]

The last remaining item before starting the truck was the under dash wiring. This mainly consisted of connecting all the wires from the LS swap that needed to be tied into the truck wiring. The bulk of wires coming across the top of the steering column are what were added from the swap. This includes truck power to the firewall bulkhead, clutch switch signal, brake switch signal, temp gauge, fuel sender signal, CEL, OBDII port, and 12V keyed signal. I also ran wires for the VSS and tach but do not have gauges to utilize these signals yet.



Turning the key to the ON position demonstrated that my CEL is working. This light should be on when the key is on and goes out when the truck is started. I also checked the OBDII port and scanned the PCM which returned no codes.



After finishing the wiring, it was time to set the truck back on the ground and finally start the engine!



I made sure to prime the fuel lines before trying to start the engine. After a few revolutions of the motor it fired right up! At first it was surging a bit, but after it warmed up the idle leveled out.

First Start

The only real problem encountered was the giant puddle forming under the truck. This turned out to be transmission fluid and coolant. The trans fluid was due to the lack of driveshaft. The coolant was due to a leaking heater core. Surprisingly, the local auto parts store had one in stock. After a quick trip, we had this repaired and the truck was alive again.

Idle/Rev

Overall, everything worked as it should. After the engine was up to temp it idled away smoothly. The electric fan also came on which confirmed that was working. The only thing that I was disappointed about was actually the exhaust. The Black Widow mufflers do not sound as good as I thought they would. At idle they are decent, but they really scream and get raspy at higher RPM. On deceleration they are exceptionally garbled and inconsistent. My next step here is to add some high flow cats (which I was going to do anyway) to try and even out the tone and reduce the rasp. All things considered, this isn't a big deal considering this is the only thing that needs attention after the first start.

[zicc1835]

Lots of progress 2 forward 1 back and then clean up the mess and then a good night of sleep I’m liking the PO1s

[clay68c10]

Man, that’s great! It’s a good feeling to have one fire up nice AND have no codes in a swap like this.
I like your location for the charcoal can. I’ll be using one also.

[cornerstone]

Outstanding! I personally think it sounds awesome. I'll be looking forward to a full report on it's drivability, power and handling characteristics. Well done as usual my friend.

[hewittca]

Originally Posted by zicc1835

Lots of progress 2 forward 1 back and then clean up the mess and then a good night of sleep I’m liking the PO1s

Yes, that has been the way so far! It's still progress though so I'm happy with that. All in all, it was a successful first start with no real issues. As for the PO1s, I do kind of like them as well but I've already set them aside for someone else. I just threw them on one more time to see how it would look.

Originally Posted by clay68c10

Man, that’s great! It’s a good feeling to have one fire up nice AND have no codes in a swap like this.
I like your location for the charcoal can. I’ll be using one also.

Definitely. At this point, there isn't anything that is telling me there's something wrong with this engine. It sounds good, idles smoothly, and is responsive to throttle input. I do have that low compression number on cylinder #2 lingering in the back of my mind. I'm wondering if I should recheck it now that I've knocked the cobb webs out of the engine, although I'm kind of scared to!

Originally Posted by cornerstone

Outstanding! I personally think it sounds awesome. I'll be looking forward to a full report on it's drivability, power and handling characteristics. Well done as usual my friend.

For sure that is the next short term goal. The only thing keeping me from driving it around the block is the lack of driveshaft. I need to shorten mine 3.5" before I can install it. I'm getting that done this week, so hopefully within the next two weeks I will be able to take the truck on its maiden voyage.

[68bowtie]

Really great truck, I love the P01’s.

Remind me what you did with the paint. Is that just a coat of wax? Looks good…

[hewittca]

Originally Posted by 68bowtie

Really great truck, I love the P01’s.

Remind me what you did with the paint. Is that just a coat of wax? Looks good…

Thanks! The paint was all original but very oxidized when I got the truck. I just hit it with Meguiar's Mirror Glaze M10508 Ultra-Cut Compound and a medium pad on low speed. I have not put any finishing polish or wax on it yet, but definitely plan to do that before I start getting it out in the weather.

[coldrider]

Congrats on the successful first start, it looks and sounds great!

[hewittca]

I decided to pull half the exhaust back out to install catalytic converters. I originally had intentions of doing this anyway, but after hearing the exhaust I wanted to move this up the list of things to do so I would know for sure what the truck would sound like. I went with some affordable high flow cats from Amazon, which actually turned out to be nice quality. I've read mixed ideologies about whether or not cats will change the sound of a vehicle. After installing them, I will say they did change the sound some, but it is subtle. Idle and accel sound the same, but decel sounds smoother and less raspy. It's more noticeably different in person than in this video for some reason. Overall, I am satisfied with it enough to keep moving on to other things.

One unintended consequence of adding cats was increased temperature under the truck. The floorboard from firewall to under the seat gets so hot you can barely touch it! Honestly, I can't say for sure how much hotter this is than without cats because I didn't touch the floor when I ran the truck before. Regardless, it is too hot to just leave it as is. I am currently brainstorming on how to add some sort of heat shield or wrap on the exhaust.

Cat Install

[zicc1835]

sounds great ....yikes about the heat ....BB had heat shields that screwed into the firewall not sure if you are familiar with them I have one could send you a pic you may be able to fab something similar and attach to the floor boards with some spacing

[clay68c10]

I'm going to use some of this floor and tunnel shield, it should keep the floor metal cooler and works well combined with under carpet pad and insulation.
https://www.designengineering.com/pr.../heat-control/

[hewittca]

Finding time to drive out to Winston Salem to drop off and pick up my driveshaft was perhaps one of the trickiest parts of this build! Many people have told me that Oliver's is the best and only place to get quality driveshaft work done anywhere near me, so that's where I went. The NV3500 required 3.5" out of the front shaft compared to the original 3 speed. I also had them install new universals and carrier bearing. I welded the baseplate of the carrier mount since they normally fail there.



To get the angles right (at least based on my original measurements) I had to add a 1/2" spacer to the plate I used to flatten the bottom of the crossmember. I didn't actually remeasure the angles with the driveshaft reinstalled, but I should have (more on this later).



The driveshaft fit perfectly and I had it installed in no time. You'll also notice the exhaust wrap that I added. This did help reduce the rate at which the floor heats up, but if you let it sit and idle long enough the floor will still reach the same temperature once it's heat soaked.



I figured I should add a tach since this truck is manual. I don't want to drop the cash or brain power required to make a stock tach work (which I don't even have), so for the short term I am using an Equus tach. Admittedly, it is quite cheaply made but it does a decent job of displaying RPM. It also matches the interior fairly well. This will be around until I get to redoing the interior (sometime next year).



...And now for the pivotal moment of the first test drive! It was late and I have no tail lights yet, so it was just a quick 1/10 mile loop around the driveway. Everything felt like it should, so I was excited to take it out again in the daylight.

First Drive

This brings us to today. I was anxious all day at work to get back home and hit the road in the truck.



I started slow with a short 1 mile ride out and back with my wife. Then my kids took turns going for a ride as well, ending with my son and a 15 mile loop.

First Road Drive

Through the Gears

Overall, the truck performed very well considering how many things I have changed and rebuilt. There was nothing detrimental that would keep me from throwing the bed on and driving it as is while I continue to tweak and improve the truck. Here are a few observations that may or may not need attention:

1. First and second gears in the NV3500 are quite short. It almost feels like I am spinning the rear tires because the RPMs jump up so quick and it doesn't really feel like I am going anywhere. Other than that, the transmission shifts smoothly and functions properly.

2. The intake that I used on this truck makes a noticeable swoosh sound whenever I hit the throttle. I'm not a big fan of intake noise, so I will see how long I'll go before I want to change this. Hopefully once the hood is on and I add sound deadening and carpet I won't hear it as much.

3. There is a driveshaft vibration in 1st and 2nd at low RPM. Once I'm cruising along in 3rd and above the vibration goes away. I will definitely need to look at the driveshaft angles. My last truck had a vibration after flipping my carrier bearing and all I had to do was adjust the angles. I'm hoping it's the same solution here.

4. The manual steering sucks! I don't know if my memory is failing me, or all the suspension changes I made affected steering, but I definitely did not like the steering today like I did the last time I drove the truck before all this work. The wheel was very heavy at low speed and hard to make tight radius turns. At speed it felt pretty good until I had to turn the wheel past 10 and 2 and then it got heavy and less responsive. I will definitely be looking into a power steering swap.

5. Heat is still an issue even with the exhaust wrap. While cruising around the air flow keeps the heat at bay, but as soon as I sit and idle the floor temp starts to spike again. At one point I stopped to take some pictures and left the truck running. When I got back in the floor was quite hot. I believe I will have to add additional heat shielding under the floor.

6. The truck feels very small with it this low. It was a strange feeling driving it. I never felt this way before driving it or my old truck, but it's something I will have to get used to I suppose. I do like the way it sits so I won't be changing the ride height!

7. With the caster mod my springs rub the front edge of the cup in the crossmember. I'm not sure how I will remedy this, but it does need to be resolved. Any time I go over a bump I can hear the spring pop over this edge.

8. At most RPMs the exhaust actually sounds pretty good. It's not even that loud in the cab and I currently don't have any sound deadening or carpet installed. There is only a short RPM band around 2500 where it really drones, actually, its more like a humming. It's kind of a strange sound. I'm hoping once the bed is on and the tail pipes are installed it will be better.

I believe that is it for now. If I've lost you by now that's ok! I was trying to get all this down before I forget it. From here, I plan to address a few of the items above and continue installing the remaining body panels. In addition, I will put more validation miles on the truck to work out any remaining bugs.

[clay68c10]

That is awesome, nothing beats that first ride! I love the pic with your son, he looks excited.

I would say that your hard steering is from the extra caster, the stock setting for these guys was pretty minimal to make them steer easier. That said, I'm adding extra caster in on mine also.

I forget how small these trucks are till I get in one. My old 68 longbed was about the same length as my 93 shorty.

[cornerstone]

Great update with huge progress! Well done.

[hewittca]

Originally Posted by clay68c10

I would say that your hard steering is from the extra caster, the stock setting for these guys was pretty minimal to make them steer easier. That said, I'm adding extra caster in on mine also.

That's a good point, I forgot I did that! Thank you for reminding me what I've done to my truck . Now I'm wondering if it's worth going back on that mod, or just keep moving forward and do the upgrade to power steering.

[clay68c10]

Happy to provide a reminder
You could un-do it, but it won’t track as nice at highway speeds. Nor will it want to return to center as strongly after turns.
I say go with power, it’s easy on these trucks.

[hewittca]

Yeah, I've already started to look into what I need. I never considered it before because I thought I would just keep my manual steering. I ditched the truck power steering/alternator configuration when I converted to the low mount alternator. I guess now I have to add one of the high mount power steering pumps. So much for cleaning up the front of the engine. I wonder if the install is as simple as connecting the LS style pump to an original style power steering box.

[clay68c10]

If you have access to an alignment machine you could play around with the caster and see how it goes. I can say that my truck originally was manual steering and it was a mofo to turn. This was back when I was a high school kid. I've driven some other manual steering vehicles and they're all similar. Unless you're moving, it's difficult.

If you get the LS truck style pump, it should work fine. You can swap the pressure output fitting and use the old style lines. I don't know about the other types of pumps.

Either way, it's awesome that you have it up and running.

[zicc1835]

Originally Posted by zicc1835

sounds great ....yikes about the heat ....BB had heat shields that screwed into the firewall not sure if you are familiar with them I have one could send you a pic you may be able to fab something similar and attach to the floor boards with some spacing

here is a picture of the BB heat shields they are only approx 4X10 or so but you get the idea fab something longer and spot weld some nuts to the floor boards get some spacing between them the floor and your pipes ....maybe shield that heat were going to shield the sun you know to control the climate

truck sounds great love the stance and may have to borrow them tail lights for my maiden voyage .....

[coldrider]

Congrats on getting it moving again! And your punch list doesn't look too bad at all. Seems to be running really well, did you retest compression on the low cylinder?

Sweet looking truck, its gonna look even better all put back together

[72 tigger]

Great progress! Really a cool truck!

[hewittca]

Originally Posted by coldrider

Congrats on getting it moving again! And your punch list doesn't look too bad at all. Seems to be running really well, did you retest compression on the low cylinder?

Sweet looking truck, its gonna look even better all put back together

Thanks! I have not rechecked the compression yet. I'm kinda scared to because it does run so well! That should be my indication that it probably is ok now and I really should recheck just to make sure.