Reprise's 2003 Sierra Build Project <name TBD>


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So, as we all get used to 'life under coronavirus', I've reconsidered having the rear axle noise diagnosed / fixed before beginning my long-planned (and long-promised!) build. Partially, it's because I'm now suspecting that the noise I'm hearing may be U-joint / driveshaft / pinion related, and that whichever it is, it's in 'early stages'. Might be misplaced optimism, but I'm sticking with it, for now.

Which means... this is now a perfect time to start the build, in earnest, since my personal mobility is being limited right now.
- This won't be a 'one-to-two day' project (although I'm sure some of you could do it in that time) -- so, if you're interested in following, you may want to 'subscribe', so that you'll be notified when I post something new / worthwhile.
- For the same reason, don't expect 'daily' updates.
- If you see I've done (or about to do) something 'wrong', don't be afraid to voice your concern. I intend to explain why I'm doing certain steps, as they come along. (but I'm also aware that my postings easily become longish, so striking that happy medium may be a challenge, at times!)

Here's a couple photos of our 'patient'...


This first one is how I 'got' the truck. 2003 Sierra 1500HD, with about 230K.
You'll note the C3 / Denali grille / turn signal housings / bumper cover (which is not flush due to the previous owner not using the special brackets required with that cover), along with the H2 rims / big-ass 315/70/16s.
The owner before him had a CB Radio in the truck (that's what those antennas behind the cab are for).
This truck spent the first half of its life in Texas, and there's almost no body rust / only surface rust on the frame. Lucky me.
Those bulging rear fender flares indicate that this truck has Quadrasteer. Thankfully, the previous owners didn't use this for towing boats, as the system is still operable. Incidentally, those flares are... fiberglass, meaning that they'll never rust, like the rear wheelwells normally do. The rest of the bed is steel (and it has a Line-X bedliner, which is in excellent shape, for a 17-year old truck. Lucky me, again.

Over the last several months, I've replaced most of the front suspension, tires / wheels, tailgate (which was dented), the rear axle (a 35-spline Dana 60 with kingpins), new rear hubs (which are like front hubs on a 4WD truck), caught the truck up on maintenance in various other areas, replaced the Flowmaster with a stock muffler / tailpipe, and gotten it to this point:


Yeah, those are Chevy center caps - sue me. LOL Tires are BFG 265/70/17s (highway tread; I tow with this truck, and don't leave pavement). Those are new headlamp / turn signal housings, and the OEM grille / bumper cover. Added a soft tonneau & nerf bars (you don't see the passenger one here, but it's there now)

The gap you see between hood / fender / grille is because I forgot to latch the hood before taking the pic (oops).
I also turned on the QSteer in this pic, to emphasize the 4WS, but you can't really tell, here (it moves a maximum of 14 degrees, so it's subtle). Oh well...
Yeah, it's dirty. Sue me again.

Drivetrain on this beast is an LQ4 6.0L and a 4L80E, to go along with that Dana 60 rear (which has a 4.10 gear). While my previous 1500HD had a lot of torque, compared to the 5.3L Envoy XL I was towing with, this motor is even stronger. Which makes me think it's got a tune, at the very least, and maybe some aftermarket parts. We're going to find out, as I plan to replace / upgrade the following:

- Heads (with new rebuilt 317s)
- Tow cam / lifters / springs / timing set
- Oil pump (not 100% sure on this, yet)
- Intake (and I may relocate the knock sensors to the Gen IV locations on the side of the block)
- Items which get touched on the way to the cam (like the water pump, hoses, etc.
- Tuning / dyno
- Couple addn'l appearance items

All of the above will be on top of the stock (?) bottom end, which has good compression / power / oil pressure, and doesn't burn / leak oil (which is why I may forgo the oil pump upgrade). I also had Blackstone do an oil analysis to make sure that wear metals on the engine looked good before spending $$$$ on this project. After doing the intake gaskets & killing off another vacuum leak or two, this thing is running like a top now (outside of the noise in the rear end that I mentioned at the beginning). But... I want 'more' (typical American...LOL)

Since the 6.0L has a rep for having a bulletproof bottom end, we're going to rely on that, for now. At some point, depending on how these mods work out, I may decide to put on a turbo setup (which works better than a supercharger, at elevation) - if I go that route, I'll probably get a spare block and build it up, given what I'll be spending on the turbo(s).

So... with all of that said... let's get started tearing this beastie apart!

(to be continued... )


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If you decide to re-locate the Knock Sensors... Look into the Clearance Issues for the Header Installation... especially if long Tubes are your Choice. What an Awesome Truck, Brother!


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TY, @MRRSM ! Appreciate the kind words, re: the truck. Still lots of work to do.

At this point, I doubt I'm doing headers... here's why...
- While I'm exempt from emissions testing with this truck, due to the 8600lb GVWR (amazing, in IL), and could delete cats / O2 sensors... I'd rather not do that.

- My intent is to enhance midrange / upper RPM HP & torque, where possible, for towing at elevation. 'Shortys' won't be much improvement over the OEM manifolds, and as for long tubes... well, there's the cats to deal with, that I'd like to keep.

- I don't want to make the exhaust drone while driving on the interstate. That's why I took off the Flowmaster (and while I did lose a little bit of responsiveness afterward, as measured by the 'butt dyno', I didn't regret going back to stock).

- If I do a turbo down the line, I'll have to rework the exhaust. Until I decide, I don't want to spend the time / $$$ to do it twice.

TL; DR - we'll see, but for now, I'm hanging on to the stock exhaust.

Spent the afternoon degreasing a set of valve covers and a front crank cover I picked up, thinking I was going to paint them (and wanted to get that done in the garage before putting the truck in). Then I ran across the option of powder coating, and requested a couple of quotes to have it done. So I may not be painting those parts, after all.


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FWIW... The inexpensive POR-15 "Starter Kit" in either Gloss Jet Black or what looks like the Red-Orange color of the paint on Jay Leno's Maclaren MP412C for contrast vs. the Blue Paint on your Truck would be PERFECT. This Stuff in either color would give you a durable, attractive finish on those Aluminum Valve Covers and other Cast Iron Suspension, Brake Parts and Frame Areas, too:

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Sometimes I recognize parts I'll need ahead of time, or at a certain point, and buy them beforehand. Or I find a good deal, or they'll save me time, etc. Sometimes all of these things. Such is the case with today's update.

With the amount of room I have to work in, any painting I'd have to do would need to be before the truck went in the garage. Since I wanted to dress up the engine a bit (nothing really fancy), I picked up a set of spare valve covers and a spare timing cover. I think I got these for $25 for all three via CL.

I didn't just want the valve covers painted -- I wanted a 'crinkle' (or 'wrinkled') finish. As it turns out, VHT makes some paint that is supposed to do exactly that, although colors are limited. So I picked up a couple of cans of that, along with some VHT primer. A couple of shots...


The observant reader will note that I left the timing cover seal in place. Popping it out after the paint dried produced this nice-looking result:


To activate the wrinkle/crinkle, VHT specifies 200 deg F for 1hr. Since I didn't want to potentially ruin my household range, I broke out the heat gun. However, all I did was bubble the paint off in the spot where I tried it (the paint is rated to 500F 'intermittent', so I guess they want the heat to be exactly (?) 200F. For now, we'll put these aside, as we're not going to need them for a bit. If anyone's used their household oven for VHT-style paint, and didn't ruin their oven, let me know. I still have time... lol. Otherwise, they'll get their 'curing' after they're installed on engine.

When I first started imagining this project, I always envisioned removing the heads & replacing the lifters when the new cam went in. After calculating what it would cost to recondition the heads (and potential extra costs of acquiring a new one if a crack was found, I decided to pick up an already reconditioned set, to save time / effort (also, '317' castings are supposedly known for developing cracks; you find out via pressure testing the head). Found a nice set of 317s ready-to-go; I think I picked these up for $225 on CL a little over six months ago. I double-bagged them and put them away; when I brought them out, they looked like this:


Yeah, that's rust on those springs / retainers. So, the lesson for all is... if you're going to store heads, coat them with something so they don't rust!

In my case, I wasn't keeping the springs anyway, so I stripped them out, gave the heads some additional cleaning, and replaced the springs with these...


No, those aren't blue to match my truck... they're GM LS6 springs, colloquially known as 'blue beehives'. The retainers / locks are the matching LS6 components. About $80 for the springs, close to the same for the retainers (they're titanium, IIRC), and the locks were $40 (? - not sure, but I'll look it up). Add $17 for a spring compressor (a cheapie, but worked a treat) to swap everything out with, and another $17 for a set of digital calipers to take some measurements with (I'll get into this, if people are interested, although I didn't take pics of me actually taking the measurements).

Why'd I choose these springs? Because they're a very cost-effective (& popular) choice for cams up to .550 in. lift. The stock-style springs wouldn't handle that amount of lift, plus they had 230K on them (you'll 'hear' me saying that a few times during this build). I knew nothing about the springs the new heads came with, so didn't plan on using them. The heads came with new seats / seals already installed; valves are stock LS (no fancy sodium-filled, etc.)

Before I started the project, I had gotten a copy of this book (available via Amazon; I got the Kindle version for $14 (had to look it up to get the pic, so here):


I find this book pretty useful. While I'm not rebuilding the short block / rotating assy at this point, I may at a later time. I do refer to it often.

That brings me to why I selected another set of 'stock' 317s, vs. going with the 'hot' 799s / 243s...

I did consider heads with smaller combustion chambers. But after speaking with a local machine shop resource, I decided to keep with the 317s, and not have them worked further (e.g.; porting). There's a couple of reasons behind that.
One is my intended use (towing / torque, not max HP / racing).
The other is a desire to be able to use crap gas. Out west, as you get into high elevations, octane is lowered -- the 89 RON that I get at my local gas station here in IL becomes 86-87 RON (as labeled on the pump) in Montana, for example. E85 is another option that I want to be able to use (as it is higher in octane); you see that used frequently up in the mountain areas, as well.

At 8mpg with the trailer on the back, I'd rather not be stuck buying premium. And with a 26gal tank (only size with a CCSB, in this gen truck), fillups come often, on the road. Cha-ching!

Finally, the low-compression 317s (9.4:1 stock) are considered a great option for boost. While I've always salivated over putting a blower on an engine, it turns out that a turbo would be a better option for this truck, and towing, as turbo-equipped vehicles do better with less available air than a supercharger. So, you could say, I'm planning ahead a little bit. If I do it as a 'stage 2' project, I won't be going crazy with the boost - most likely sub-20lb. But that's a ways down the road. And I need to edumacate myself on turbo building / tuning, first.

And that's today's update. Questions / comments, as always, are welcome.
Also, while I'm listing pricing here, it's not intended as a 'brag'... only to indicate what this costs me, in case someone else is looking at doing it. If I swung a really good deal on something, I'll indicate same. I do try and look for best deal available (from reliable sellers).
If you don't like seeing the running costs, let me know (actually, let us know if you do, as well).

So far... (I'll try and get this into a spreadsheet format later).
All costs in USD, unless indicated, but DO include shipping
Labor costs are not included, and you should not assume I complete anything at 'book rate'. If I could, I'd be a pro.

Timing / Valve covers - $25
Paint - $30
New 317 heads - $225 (deal - roughly $100 under similar; twice that if I rebuilt mine)
LS6 springs/keepers/locks - $208
Tools (as above) - $34

Total so far: $ 522.00

Next up: I replace a rear O2 sensor (not part of build, but want to do it before disconnecting exhaust manifolds). I'm not going to document changing this out; just making a note of what I'll be doing before picking this back up in earnest (with parts disassembly)
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do you have 220 in your garage? maybe, you could find a "junk" stove, like the range part quit working but the oven still works, for free or really cheap. use it for what you need and haul it in for scrap.


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@Beacon - No 220VAC. And even if I did, no room to put in a range. Can barely fit the truck in!

Here in the Land of Lincoln, a majority of us have basements, but the energy source of choice for cooking & heating water is natural gas, not electricity. As a side note, we have the most (?) nuclear plants of any state, but pay a rather expensive KwH rate, 'cos it cost lots of coin to build those plants in the '70s & '80s. (That reminds me to check on when those plants are due to start coming up for retirement.)

TL; DR - Appreciate the idea, but not feasible for a couple of reasons.
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