1971 Chevy Suburban Redux

Last weekend I picked up my GM 6.2 diesel motor and matching 700r4 transmission. More info and a few photos to come on that. But when I say I’m going green, I mean, literally going green. I was driving through an industrial area in town, and I spotted an old Chevy pickup that had been restored, and it’s just the color I’ve had in mind… I popped in and talked to the guy that built the truck and he was nice enough to give me the paint code. Score!

The color doesn’t translate great on-screen, but it’s a really desaturated green or olive color. This is actually a late-model GM under hood paint code.

Here are a few pics of the truck. Not a lot of long straight panels on this truck, but the doors were STRAIGHT. This truck was slick as glass…

The significance of the date in the title of this post, is that after removing the 1971 front clip, this classic Suburban will never look like at 1971 again. When I put it back together, it’s getting a 1967 front clip. That’s not the topic of this post though… the reason I’m removing the front clip right now, is to make it easier to pull the gasoline powered Chevy small block 350, and replace it with a diesel powered GM Detroit Diesel 6.2 liter engine. Since my garage is small (for a Suburban at least), and since I don’t have any axles under the truck right now, pulling the front clip makes things worlds easier.

Pulling off a front clip on full-framed trucks like this is pretty easy… just a lot of nut and bolt work. My older son even spent some time helping run bolts out with the air ratchet.

The hood came off first…

Then the grill and bumper…

The grill is actually in pretty good shape compared to a lot of these that I’ve seen. The aluminum grill frame isn’t great, but if you were creative, you could fix it probably (which is what I was going to do before deciding to go with the 1967 front clip). The egg-crate grill insert is really nice, with no missing sections, which seems to be a problem with these older inserts.

Moving on, then came the fenders. Most of the nut and bolt work is here — on the fenders. Each fender mounts to the radiator support with several bolts, and to the cab, and to the fender liner. Then, once you’ve got them off, you still have to remove any accessory brackets, and the hood hinges (which I’m doing here)…

The radiator support comes next, but I’ve left that attached for now.

This weekend I’ll pull the radiator support off and get the engine out. I have yet to confirm whether the radiator support for the 1971 is the same as the 1967. I have one from a 1967, but the lower half is rusted out, so I may end up cutting and grafting the two together if I need to.

When I get a chance, I’ll also post some side-by-side comparisons between the 1971 and 1967 Chevy fenders and hood when I get a change. It seems like I see a lot of questions online about interchangeability of these parts.

Otherwise, that gets us pretty caught up. I loaded a bunch of the extra parts into the back of my pickup to get them to storage…

And E helped me move the hood back in the garage for the time being…

He needed to take breaks every few feet, but he’s still a good assistant…

All of the parts from the 1971 Chevy Suburban front clip are for sale, by the way. I’m also going to sell the front fenders from the 1967 front clip. Make me an offer if anyone is interested. None of the parts are perfect, but all of them are workable. If noone wants the 1971 hood, I’ll probably make some wall art out of it… which might be kind of cool…

This weekend the motor and tranny come out, and things will get really interesting. Here’s a little teaser: body-off…

My arms got a little crispy on Saturday. I spent a couple hours welding up some wheeled dollies for my jack stands, and I got a little sun burn from the welding arc…

It starts on my forearm, just above where my welding gloves were, and ends right at my t-shirt sleeve. It got a little warm on Saturday for a jacket, but I guess I should have at least put some sunscreen on…

Either way, I managed to get some wheeled dollies done, so I can put my jackstands on the dollies, and wheel the Suburban around the garage without having to install my axles.

I built four of these out of 3/16″ angle iron, with four 330lb steel caster wheels each.

The classic Suburban is still massive, so setting it in motion is a chore, even with caster wheels, but this helps. I started pulling the front clip off, in preparation for pulling the engine/tranny. More on that later.

So, what’s the moral of this story… no naked arc welding. Gloves and a mask just don’t cut it.

I’ve got some work to catch up on at the office this weekend, but the weather’s supposed to be pretty nice, and if I can squeeze some time out in the garage, I’m gonna. Last weekend was great too, and I did manage to get a few things done.

Last week I mentioned that I got new wheels and tires. I got two of them mounted to the rear axles, and they look pretty good. I had cleaned and painted, and replaced a couple of gears in that GM 14-bolt semi-floater several months ago, and the only thing remaining was getting brake lines bent and connected.  Last weekend I did manage to get that done, so the rear axle is really ready for gear oil, and install. Now I can set that one aside until I’m ready to put it all back together.

I still need to rebuild the front axle. it’s a 3/4 ton GM 10-bolt front end. I have bet to pop the cover on it, so I hope the gears are all good. I’ll probably go through the same rebuilding process with the front that I did with the rear eventually, replacing bearings and seals, all the brake hardware, and putting a nice coat of POR-15 on it. That’ll probably come in the next few weeks. Here’s a shot of the 10-bolt axle:

I actually had a hard time confirming that this was a 10-bolt axle. It looks similar to a Dana 44, and most of the pictures and diagrams online show the differential cover as a pretty rounded shape. Mine looks like this, with a flat spot on the upper right:

Anywho, that’s gonna need some work, and I’ll get to that soon.

What I’ve also done in the meantime though, is remove and sell the Dana 44 and the HO72 rear-end from under the Suburban. Those were 4.10 gears, and just not what I wanted on for a highway truck. With limited parts available for the HO72, I figured it’d be easier to just swap the axles out entirely. the new ones have 3.23 gears… and that should get me good fuel economy.

Here’s a pic of T pumping the cherry picker to get the Dana 44 lifted up and in the back of my pickup:

Any now the Suburban is completely immobile:

The only other big news from last weekend is about the interior… I got a new one, from a late-model Chevy quad-cab pickup. The rear seats appear to be flip and fold just like in the Suburbans, so these ought to work perfect:

It’s the nice dark-grey velour, with the center jumpseat that folds into a console. This’ll give me 6 seats in the first two rows, and I’m thinking I’ll make some fold-up jump seats in the cargo area, rather than the third full bench.

All of that stuff’s going into storage this weekend though — the seats, the axles, the wheels, and the miscellaneous body parts that have been cluttering up my garage. This weekend I’ll tear down the front clip, and start preparing to pull the engine, tranny and transfercase. The SB 350 is got to go to make room for a 6.2 GM diesel from an ‘89 Blazer. We’ll see what kind of progress I can make this weekend.

The tires that the Suburban rolled home on were 315/75r16 all terrain tires. That’s big… too big for my blood. I’m not really an off-roader, so a 35″ x 12.5″ tire, for my tastes, just looks silly. To each their own, and if you’re driving over sand-dunes or endlessly deep mud pits, then the bigger the better — but that’s not for me. I’m building this classic Chevy Suburban to be an honest-to-goodness sport utility vehicle: I want to be able to get along on jeep trails (actual double-track trails, not creekbeds), but cruising down the highway is even more important, because there’s a lot of highway between St. Louis and Yellowstone.

Most guys that upgrade their stock tires to a larger size seem to like beefy, wide tires. Tall, skinny tires have more of a small cult following. It seems the consensus among skinny tire proponents is that the 255/85r16 is the ideal tire size. That’s a true 33″ tire, at only 10″ wide. From a performance perspective, that’s probably really the best road manners (quietest and best fuel economy) and the best off-road characteristics in everything but super deep mud or sand. The problem is… you cannot find any sort of selection on these tires. Most of the choices are mud terrain tires, with maybe 3 or 4 choices, and there’s only one all terrain tire in that size that I’m aware of: the Cooper Discoverer ST. Even then, the ST is more like a hybrid between a mud terrain and an all terrain.

I had actually settled on a tire, and ordered a set from Discount Tire Direct. I decided to go with the BF Goodrich Mud Terrain T/A KM2 in 255/85r16. Everything I read is that they have surprisingly quiet ride, and the treadlife is really good for a mud terrain tire. They’ve got a wickedly aggressive looking tread pattern, which is maybe out of character for me, but they look cool! It all makes no difference though… Discount Tire Direct called back shortly after I placed my order, and they informed me that the BFG Mud Terrain T/A KM2 is on national backorder. Bummer. I check tirerack.com… same story.

The next closest size, and my second choice, was the 255/75r17. With the slightly larger wheel diameter, but lower profile sidewalls, the total height on those is about 32″. So I give up an inch in height vs the 255/85r16, but I keep the 10″ width. There are a ton of all terrain choices in this size, but a 1971 Chevy Suburban is a *big* truck, and I worried that a 32″ tire would feel a little small, especially since they’d be replacing 35″ tires. And with all terrain tires vs mud terrains, would they look like stock highway tires on the bug ‘Burb?

I went ahead and pulled the trigger. A couple days later UPS shows up with four Goodyear Wrangler SilentArmor tires in 255/75r17. That rubber would get wrapped around some good ol’ Cragar Soft 8 black steel wheels in 17″x8″. Here they are mounted up:

I actually really like the 75-series sidewall profile on the 17″ wheels – they’re not overly balloon-like, the way a lot of larger tires look on 15″ or 16″ wheels. Here’s a shot of the new tires next to the old 315/75r16 tires:

Clearly these 255/75r17 tires are smaller, but not too small. I’m liking them more and more. Here’s a shot of them lined up next to my daily driver, an F150 with 31×10.5r15 all terrain tires:

It’s hard to see really well against the black truck, but that photo still gives you an idea of the change.

On Sunday I got two of the new wheels/tires bolted up to my cleaned up 14-bolt semi-floater rear axle. I added brake lines to the axle this weekend too, so all it needs prior to bolting it up to the truck is gear oil. Here’s a photo of the axle with the wheels and tires.

I like it. I’m really happy with the size, and the Goodyear Wrangler SilentArmors will hopefully prove to be a nice, quiet all terrain tire, with enough tread to get me through a little slush and slop and gravel once in a while.

More updates to come soon. I made more progress on the truck this weekend, got some interior parts, firmed up on a deal for a diesel engine… but for now, it’s late, and I have work to do. Wish me luck!