[jslezak83]

Hi folks. In an effort to light a fire under my ***, I’ve decided to create my own build thread after about 7 years.

As the title says, I’ve got an ‘87 2WD Blazer I’m swapping. Years back I
was much more active on this site and with the truck. I had completed a 2.8 to 4.3 swap in 2002. A few years later I did a LB9 swap. That only lasted about a year before I spun a bearing in the motor. I found a L98 and ran that for quite a few years. I was never happy with that 350. The TPI, while torquey, was never really scratched the itch for me.

In about 2015 I picked up a LQ4 with about 118k on it I think, but I honestly can’t remember anymore. I had a 4L80E core rebuilt, bought a H3 oil pan, CPW poly mounts, and Stainless Works long tubes. Then I bought a house with a nice two car garage, put it all in and nothing fit. I got married, and that’s more or less where the trail went cold.

Here’s where she sat a couple years ago collecting dust, and getting buried behind varying piles of home improvement building materials. At one point it was completely blocked by plywood.

Playing with wires.

Motor in.

I always had plans of doing some kind of power adder, but over the years as the project sat stalled, I could never come up with a plan. As such, nothing really ever got done. Although I never tried, I’m pretty sure with the truck accessories and 145A alternator, the hood would not have closed.

Enter 2021. I changed the front end to LS3 water pump and a Corvette bracket. I plan on using the Holley low mount A/C with a Sanden 7176 compressor.

On the suggestion of @Harley, I picked up a 2004 Grand Am cooling stack and that really helped out fitting everything. The air intake, upper radiator hose and alternator were all fighting for the same space.

So here I am today, playing with my pile of spaghetti under the hood. I’ve more or less nailed down where everything is going to live. Note: Check out the 5+ years of dust buildup here from the last group of pics.

The P59 PCM will fit nicely under the battery tray, and that will really help clean up the wiring. Coolant expansion chamber is from a Chevy Cruise. Power steering reservoir is from a Pontiac G6. I used Airaid UBI pieces for the intake. Used the Loc-Tite brand super glue the interwebs says and it’s pretty solid. Once the motor position is finalized, the straight to 90 elbow will get glued and it will all be smoothed and painted.

I’m at the point now where I think I just need to hear it run. I’m not too concerned right now with fitment of everything, but I’m going to complete the wiring, plumb the fuel lines and hit some sort of milestone in this project.

 

[jslezak83]

Here are a few shots of the latest wiring routing. Think PPV / SS / Camaro. With the PCM under the battery I’ll be able to cut able 3-4’ from the Express harness.

 

[944v8indfw]

very nice following

 

[jslezak83]

Now here are my issues, all more or less with the headers and the ‘87 chassis.

The steering shaft hits hard into the #5 primary and #7 isn’t much better. Forget about column shift linkage. On the passenger side, things aren’t much better. I’m hard into the frame, and have very little clearance at the floor pan. I always assumed I’d need to notch the frame. I always hated the idea of denting the tubes to gain clearance, but it won’t take much to clear the floor. I wish @84blaze was still active here. I’d love to discuss how he got the Stainless Works headers to fit the early 1st Gen chassis. All the pics in his thread have the body sitting on blocks on the frame.

As I sit here working on my wiring, Q&A time for you 2nd Gen guys. Which side of C101 goes to the body, male or female? I grabbed a C101 for tach, SES, ect. But didn’t think to check. Functionally, it doesn’t matter, but thats the level of detail I’m trying to put in here.

 

[944v8indfw]

You might take a look at the Hooker swap steering shaft or the Jeep shaft mod to gain clearance. There are a couple threads on the forum about the Lokar cable shift setup.

 

[944v8indfw]

Hooker Headers 71223022HKR Hooker Blackheart Steering Shafts | Summit Racing

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www.summitracing.com

 

[jslezak83]

There are so many more solutions available now then when I first got this started.

I’m not sure that the Hooker shaft will help, because it’s still the 3/4” DD portion is where it’s hitting. Believe it or not, the Jeep shaft was even worse. There is a rubber isolator right at that #5 primary. I think I may have to go with a 3 piece shaft.

I like the idea of the Hooker manifolds, but I feel like they are too much of a log style. I wish the Summit G9084 or the flanged p/n fit better. Those have to flow better than the S10 manifolds.

Back in the day, I bought a set of the CPW long tubes. I still have those hanging on the garage wall, but they didn’t fit that great with the 4L80E. I think next time I break the motor mounts apart I’ll slip those in and see if the fit is any better. 1 3/4 vs 1 7/8” will have to make a difference.

 

[Rhotpursuit]

Hooker manifolds are pretty popular. There must a half a dozen of us here that are running them.

 

[oldeerslayer]

I am.
What is the service number of your P59. Not all will work well with an S10 because some worked with 12V A/C requests and some don't. Those are looking for a data feed.
lt1swap .com has a new A/C page that lists which do and which don't. From my own experience I know the 6242 doesn't work and the 6243 does in an S10.
Looks like you lost your A/C. So it probably doesn't matter. If I ever do another LS I'm simply going with the tried and true 0411. I don't see where the slightly faster P59 makes any difference. It doesn't make the truck faster. They are primarily for running crap S10's don't have. Like variable A/C compressors. Which the 2.2's had long ago.

 

[jslezak83]

I’ve seen the posts recently about the Hookers. I’ve been silently following you guys for about a year. I just don’t think they will offer much benefit with my early chassis.

I honestly sometimes wish I just bought an L31 crate engine and called it a day.

Hooker manifolds are pretty popular. There must a half a dozen of us here that are running them.

 

[jslezak83]

@oldeerslayer, I have the ‘243 that came from the Express donor. It has the DBC and 12V A/C request. In my 20s I had no use for the A/C and gutted it. Knocking on the door for 40 now, it’s a must have.

My plan is to wire the request signal through the original cycling switch on the suction side. I will probably add a high pressure cutoff when I ever get the lines made. This will all run a fixed, cycling compressor.

I also grabbed wire and the pressure sensor from the Grand Am. I plan to utilize that to have properly functioning fans.

 

[manbearpig]

The pressure sensor is probably not going to be very useful with a fixed compression compressor. The fans run at a constant speed with a variable system, you don't want them to slow down with the AC running.

 

[oldeerslayer]

Sounds like you know what your doing.

 

[jslezak83]

The pressure sensor is probably not going to be very useful with a fixed compression compressor. The fans run at a constant speed with a variable system, you don't want them to slow down with the AC running.

From what I have read, HPTuners will allow you to select a fixed or variable compressor, and controlled via an analog or serial signal. You can feed the PCM the 5v pressure signal to get the two speed fan control. The request signal is then cycled through the S10 pressure switches.

I by no means claim to be an expert on this, it’s only what I’ve read online. Hopefully, when the time comes, everything functions as intended.

 

[manbearpig]

That's cool, I did not know that. Let us know how it works out.

 

[oldeerslayer]

HPT will let you choose fixed or variable if the particular PCM you are using can do either.
His 243 PCM I don't believe is capable of controlling a variable compressor. The cycling of a fixed displacement compressor can be cycled with the S10 switches. Which is how the Express vans did it.

 

[manbearpig]

I've been dipping my toes into the Megasquirt world, I'm pretty sure a factory PCM won't do all of the things I want to do. Interesting to read about someone trying to do something creative with one though.

 

[420blazer03]

Sweet build, I will always stay away from this kind of stuff just for the wiring, I can’t fathom any of it. Can’t wait to see you get her running though, thats gonna be a bad lil truck.

 

[goes2fast]

No updates?

 

[jslezak83]

Well, that went fast! When I last left off here, it was April. It’s been really hard to find the motivation to work on this truck. Sometimes it feel like some of the hangups I’m facing are insurmountable. To scratch some sort of performance itch, I resorted to garden tractor pulling with an old Cub Cadet this past summer (I suffer from what I call Project ADD).

I took advantage of some time off work and the 50* weather we’ve been having. The motor came back out and I’ve been putting what I hope are the final touches on the harness. I’m trying to juggle a clean layout that’s still serviceable, with the eventual goal of a LSA blower. It’s just easier to get to everything with the engine out. I also need to drill out the standard broken exhaust manifold bolt at the back of the passenger side cylinder head.

I need to order more braided loom and heat shrink, but I hope that I can get everything on the engine wrapped in the next week or so. Then I can put the engine back in and make the final connections to the fuse/relay center, and cut and repin everything at the PCM. The added length of the van harness really helps out here.