1971 Chevy Suburban Redux

The rain the past couple of weeks has hampered my bodywork efforts (can’t have the sub sitting outside with the doors off while they’re in the garage getting worked on). But maybe the timing was good. I decided to sell the Quadrajet carburetor I was planning on rebuilding, and the Holley 4-barrel 4160 I just rebuilt (which is for sale now, btw). In place, I got a brand new Edelbrock Performer 1405. It’s their 600CFM 4-barrel carburetor, and the 1405 is the manual choke version.

It’s packaged nicely, and is pretty much a bolt-on-and-go upgrade, especially since I already have an aluminum Edelbrock Performer intake manifold.

You can see the obvious difference in layout when compared with the Holley 4160 4-barrel carburetor. With the big fuel bowls on the front and back of the Holley they look at lot different.

I believe the Holley is capable of flowing 650CFM, and only 600 for the Edelbrock, but that’s fine with me. I’m not making a race car. And actually, I didn’t expect this, but the primary throttle bores are actually a little smaller on the Edelbrock, so hopefully that means better fuel economy. Everything I’ve read and heard indicates that the Edelbrock is not a spread-bore carburetor, but maybe I don’t understand the terminology, because the primaries here are clearly smaller than the secondaries.

The primaries on the Holley, on the left, you can see are the same size at the secondaries, truly a square bore design. I wish I still had my Quadrajet to show for comparison, there’s an even more dramatic size difference between the primaries and the secondaries on those — and really it’s just that they have massive secondaries (they flow 750CFM total).

The install was pretty straightforward. I actually like the placement of the fuel, PCV and vaccuum ports much better, just seems like a cleaner setup to me than the Holley.

I only had one little quirk I had to deal with, and that’s where to connect the return spring for the throttle linkage. You can see in the photo below, that the throttle linkage that was on the Holley had a little tab at the bottom where the spring was attached. No such luck on the Edelbrock, so I had to fabricate one out of some scrap metal. Easy to do, but there really isn’t even any mention of the return spring location in the install instructions or the included DVD.

Otherwise, it installed really quick and easily. So no complaints there. It’s a tight fit getting a wrench on the rear bolts, and no-dice at all trying to use a socket, but no biggie. It fired right up the first time and seems to run pretty nicely right out of the box. I did a little tuning on it and overall I really like it. Seems like the throttle response is better than the old Holley. I’ve still got a little fine-tuning to do, so I’ll post some more comments later.

Just posted this info on CL, figured I ought to post it here as well…

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Hi, I have a Carter (Edelbrock) Quadrajet carburetor for sale with original intake off a small block Chevy 350. I believe it was on a 76 or 78 Chevy pickup. I have never used the carburetor, but I was told it worked when it was pulled off the original truck (this past year). I planned on putting it on my motor but never got around to it, and it’s been sitting in my garage for 6 weeks. As much as I want to replace the old Holley, I’m too lazy to get around to it.

As I said, I was told that it works, but I’ve never used it. It appears to be complete and in good shape. I debated whether I wanted to just install it or rebuild it first, since rebuild kits are pretty cheap. These Quadrajets are supposed to provide better gas mileage (smaller primary bores) and better throttle response, but still are able to flow 750 CFM in stock form, which is much more air than the Holley 4160 I have. That’s why I bought it in the first place.

Anyway, I have the Quadrajet carb, SBC intake and air filter (K&N style) for sale. I’ve got some other items from this truck I might sell/trade including the axles, tranny, etc. I’m interested in a front clip from a 67-68 Chevy truck, a 700r4 tranny, 1/2 ton axles, etc. See my blog for more info: www.1971chevysuburban.com.

Contact me through CL via email if you have any questions. Thanks!

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http://stlouis.craigslist.org/pts/1680376673.html

Contact me via CL or respond to this post if you’re interested. Thanks!

I figured out where the remaining carburetor leak is (see my last post) — it’s the throttle shaft. This is one of the items that you don’t rebuild with a regular rebuild of the Holley 4160 carburetor.

E wanted to take a picture of his old man working on the carburetor…

After pulling the carburetor off the Suburban, I went through as methodically as I could. I pulled the primary bowl off and inspected it. I did a little re-adjusting of the float level while I had it apart. I double checked all the screws and bolts, and retightened everything. As I’m inspecting the throttle shaft, I realize there’s just a tiny bit of play in the shaft. It operates smoothly, but I think I found the cause of my leak. The bearings at each end of the shaft are worn out.

You can see the slight gap around the throttle shaft on the choke side…

I did a little web searching and found out this is pretty common on old Holley carbs. I’m not sure if this carburetor/intake setup is for me yet, so I don’t want to nickel and dime myself to death just making this old 4-barrel work. So… rather than buying a new throttle plate assembly, or any other odds and ends from Holley, I decided to clean up the surface, and run a tiny bead of silicone around the shaft. We’ll see how it holds up, but it was free, so worth a shot.

I’ll be interested to see if this solves the stalling after the truck warms up. I suppose it’s possible that after 10 minutes of driving, the Suburban is up to full operating temperature, and the play there is enough of a vacuum leak to cause a problem. I think normally vacuum leaks are a greater problem when the engine is cold, but who knows.

It was only last weekend that I picked up this beast of a 1971 Chevy Suburban. As I’ve mentioned, it’s friggin’ huge. I’ve driven it around some, and I don’t mind the Hugger orange color, or the rust holes so much. I’m not easy to embarrass… but the 35″ tires and the massive lift kit is just a bit much for me. Plus, with that tire/lift combination, the Sub doesn’t fit in my garage. So, on my first weekend with this project, my goals are these: get the carburetor choke working, and lower the height down to at least somewhat normal levels.

I started with the choke, since being able to start the truck and move it around would be helpful. It’s got a 4-barrel Holley carb in it, and it looks like the entire choke assembly is broken off. I see an orphaned ground-wire connection that makes me think this originally had an electric choke on it, but it’s hard for me to tell.

As it sits, I have to start the Suburban with the choke closed… keep it running for half a minute or so… shut it off (or let it die)… pop the hood and place a spring/clip on the choke plate to keep it open… close the hood and start the car again. It does a warm start no problem, but getting going in the morning is a bummer.

It’s about $55 or so to get an electric choke kit, which isn’t a big investment, but right now, all I need is the bare minimum to make this thing easy enough to move around. Working a manual choke is no problem, so I picked up a $10 cable choke kit from AutoZone.

Since all of the choke hardware is broken off of this old carburetor, I had to figure out just how to mount this cable, but I got something rigged up, and it works just fine. Here, I have to pull the lever to open the choke, and push it in to close it, which I think is opposite of how it’s supposed to operate, but it gets the job done.

Here’s T and I up on the winch bumper working on it. As ugly as it is, that giant bumper makes a great platform for working under the hood.

So, now we’re operational, and I can start this thing up whenever I want. More on the lift/lowering to come…