PROJECT: How would a Chevrolet dealer build a shop truck in the early 1970s?

[mattfranklin]

Originally Posted by 67cheby

sounds cool !

Thanks for the kind words. I enjoy reading your builds.

[mattfranklin]

I gutted a lot of the randomly added wiring to clean things up. Then I put a clean wire with inline fuse in the proper gauge to the HEI. I was amazed at how easy it is to connect to the "IGN. UNFUSED" terminal.

I think for now I'll do the same for the choke heater on the second IGN. UNFUSED terminal. I'm still thinking about the List4555 and making it more period correct with the divorced choke, but for now it's more important to me to drive it reliably. So the electric choke it what it will be. Maybe a few pics on my day off Friday.

[mattfranklin]

On Saturday I wound up spending the time picking up a '72 hub-to-hub front end and rear end. Happy to have the parts. Now I just need some time to do the conversion(s). And take a few pics.

[mattfranklin]

Picked up a workable front and rear end, hub-to-hub from Vova last weekend. Was able to haul it home with a minivan. It worked great loading it with Nick's forklift at his shop (with three of us lifting, balancing, and sliding) and then unloading with my engine hoist on the other end (with just me balancing, sliding, and kicking it around). The one difficulty was that the minivan suspension didn't quite clear the lower legs of the hoist when I tried to slip it under. A little rocking and sliding and I was fine, though.

I was glad to get the parts in hand, but a few other smaller projects will happen before I swap cross members, axles, and get new wheels.

[mattfranklin]

Today I made good progress on the reinstalling and connecting the electric choke.

First pic is the five pounds of junk wiring that I trimmed out a couple of weeks ago.

Next is showing the where the choke wire feeds through the firewall.

Third is the fuse box showing right where I connected the choke wire (with inline fuse). It's on the lower "IGN. UNFUSED" spade lug connector, right below the same thing for the HEI.

The forth is just a side shot of the truck, because Scott asked what it looked like.

BTW, the choke now works GREAT! It starts, idles, and drives nicely -- without any frantic pumping of the gas pedal to work the accelerator pump.

[mattfranklin]

Oh, and I changed the ignition key cylinder because the key was really loose and wouldn't even go in straight unless I was really careful. It really didn't deserve a picture because it took less than a minute. Now it's nice and tight.

[sduckworth13]

Matt, you have a awesome looking truck.

[mattfranklin]

Originally Posted by sduckworth13

Matt, you have a awesome looking truck.

Thanks for the kind words. I wish I had a little more time and money to put into it. I'm following your build(s) and it(they) are inspiring.

[mattfranklin]

Finally finished up the go-kart a few weeks ago. Now the main home project is the truck.

It was a surprising amount of work to disassemble the spare '72 front cross member.

This weekend we took the power washer and wire wheels to the parts. SAFETY MOMENT: I wound up picking more than a few wires out of my shins. #1, wear safety glasses and a face shield and wear long pants.

After we brushed the parts we wiped them down with alcohol, let them dry, and started painting.

We're using black Rustoleum Rust Reformer primer and then spraying Rustoleum satin over the top. It will be interesting to see how it holds up.

[mattfranklin]

New front suspension is pulled apart, cleaned, and painted.
Front clip is off.

There is a bad zone of rust-out below the battery box on the radiator support and inner fender. Should I replace or patch? I have a MIG and some bodywork experience (as in, sure I can weld and make the metal strong, but it's kind of ugly -- still I keep getting better at it). Do they make patches yet for inner fender rust-out? Who has experience with the radiator support patches?

Pictures soon.

[mattfranklin]

Just documenting where everything connects so I won't be as confused when it's time to reassemble.

[mattfranklin]

And a few more of how the wiring harness hooks in...

[mattfranklin]

The hood came off easily and the kids were able to carry one side of it while I handled the other.

Also pulled off the front clip. It was pretty straightforward, but my 11 year old isn't quite big enough yet to lift a side. So we gently rolled it on a gym pad to get it out into the yard.

[mattfranklin]

Now the yuck starts. I didn't realize how much inner fender and radiator suport had rusted away.

I tossed in a driver side inner fender pic for comparison. It actually looks really good.

[mattfranklin]

One more shot of where the passenger side inner fender attaches to where the radiator support is supposed to be. And another one of the rusted outer fender pocket.

[mattfranklin]

EDIT: I searched a little furthr and saw tis nice write-up for the Brothers radiator support patch panel:
http://67-72chevytrucks.com/vboard/s...d.php?t=389406
Found a link for the part, too:
http://www.brotherstrucks.com/prodin...number=RSP72RH


So, now my main question:

Does anyone make a patch for the passenger side inner fender? I don't mind buying a new fender, but the shipping such a huge bulky thing just ruins the economics.

I have a MIG and do ok with it. Results are nothing pretty but I get a little better every time.

[DD1]

Nice looking truck! I like the concept you are going with. I have also learned a couple of things, like the radiator support panel being available; not sure if I need it, but it's good to know.

I need to get back in the garage!

Keep up the good work!

[mattfranklin]

Thanks for the kind words! I wish it would go faster but time and money are in such short supply.

I need to post some pics, but the engine is now out and partially stripped down.

Good news:
Piston tops all pretty clean and consistent.
Forged 30-over pistons, L2256 (at least I'm assuming -- unless someone makes an "L2256" that is cast)
Nice looking bores in all cylinders: clean, good cross-hatch and no ridge
Big Valve heads (based on visual spacing between valves may even be 2.02/1.6?)
Slightly mangled clutch pressure plate with missing bolts, and some bolts that were too long to actually tighten the pressure plate assembly to the flywheel and warped bent diaphragm fingers -- This is all actually good news because it may explain the "rod noise" that didn't quite sound like rod noise.

Bad News:
A surprising amount of sludge in the heads and lifter galley.
(I'm wonder if the engine wasn't cleaned very well when it was "rebuilt about 30,000 miles ago").
Not thick, but some surprising flakes and chunks of it.
Cast crank.
Heads are '624, that have been described in numerous places on the Internet as the the "worst heads ever"

Still Unknown:
2 or 4 bolt mains? It is the '0010 block casting and was said to be a "truck engine," so there is a chance. Hope to pull the pan find out that today.
State of the rod and main journals. Will take a look and confirm if the "rod noise" was just clutch parts failing or real crank noise. For now will use my eyeballs and plasti-gage. Not sure if I want to invest in a set of micrometers.

[geunther]

I like your concept. I had a 70 LT-1 with the original motor. I wanted to drive the thing but was afraid of damaging the original motor so I built a spare motor to the same specs as a stock LT-1. I was able to get new heads from GM, in fact I still have one (I ended up with 3). I used a 4 bolt block high nickle block but I used my factory intake and valve covers so that part was easier than what you faced. The compression was a problem with today's gas (11.5 : 1 if I remember correctly)

Anyway, great idea. And the motor was strong!

[mattfranklin]

Cool.

I'm so tempted to go for 11:1, but since my 30-over forged flat tops held good compression and the bores still look good I may stay with those.

I see that Summit has a Howard copy of the classic '178 LT-1 cam for about $150.

[DD1]

Originally Posted by mattfranklin

Picked up a workable front and rear end, hub-to-hub from Vova last weekend. Was able to haul it home with a minivan. It worked great loading it with Nick's forklift at his shop (with three of us lifting, balancing, and sliding) and then unloading with my engine hoist on the other end (with just me balancing, sliding, and kicking it around). The one difficulty was that the minivan suspension didn't quite clear the lower legs of the hoist when I tried to slip it under. A little rocking and sliding and I was fine, though.

I was glad to get the parts in hand, but a few other smaller projects will happen before I swap cross members, axles, and get new wheels.

Sorry if I missed it in the first set of posts, but why are you replacing the front and rear end? Just curious.

[mattfranklin]

Originally Posted by DD1

Sorry if I missed it in the first set of posts, but why are you replacing the front and rear end? Just curious.

To get *stock* '72 disc brakes and the rear to get matching 5-lug wheels. I could have gone with just '71/'72 spindles, but then would have had to use custom brake hoses. With the complete '72 setup I can just walk into any NAPA store and ask for stock brake parts for a '72. It saves my feeble memory from working too hard trying to recollect which custom part went where. Stock is stock.

[mattfranklin]

Where did that rod noise come from???

SHORT ANSWER: A 0.010 under crank with STD rod bearings makes a lot of noise.

LONGER ANSWER:

EXPLORING
Pulled the pan and had a chance to check the crank bearings. Yikes! There was movement I could feel and hear as I rattled the big ends back and forth. Of course there was the side clearance which is ok, but also a clink-clunk in the direction of rotation. I've not done a lot of engines, but I don't remember any healthy engines doing that. I pulled off one of the caps that was among the loosest offenders and convenient to reach: #4 cylinder. With the #4 piston and rod fully out I could measure the crank and look at the bearings.

MISMATCH!
Look at the pics and you'll see micrometer reading and a picture of the rod bearings. The later small blocks had a 2.10 rod journal diameter. Micrometer reading looked like .012 less (25 minus the 13 reading on the scale = 12) than 2.10. To me that feels like a 0.010 bearing might fit that with a nice 2 thou clearance. Note that "STD" stamped on the rod bearing! No wonder it made those rod noises even with 15W-40 oil! I'm guessing the rest are in about the same state.

[mattfranklin]

I pulled the rest of them this weekend and all of the rod journals were ten under and all of the rod bearings were standard. Wow, just wow.

[mattfranklin]

Was happy to see that the engine already had 030 forged pistons (L2256-030). I was assuming I'd reuse those. A motor machinist friend took a look at them. Bummed to find out the skirts were cracked. All of them. That could have contributed to the noises, too.

Plan to do a simple stock rebuild for now and start collecting LT-1 parts.