Re: 1987 R20 Suburban LQ4 4L80E swap
 

Here you go: http://www.summitracing.com/parts/mpe-11265
I'm sorry I haven't started it yet so I can't comment on how they sound.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Awesome - I'm just glad you have the part number and also aren't running cats. I'll be curious to see how you like them. I'll sheepishly admit the pair I bought have a 14" case and 3" in/out...

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Well, new radiator brackets from LMC won't work either. They are for a radiator way smaller than mine. I have bought every bracket from LMC and nothing works. The stock one piece top bracket is still too short also. Looks like I am going to have to start making some sort of spacer. This is frustrating, spending all this $$$ on such a nice radiator and the damn thing doesn't fit. I currently have some pieces of rubber hose wedged between the radiator and the rubber mounting pads and it seems to be secure for now, but sure would feel better if I knew it was more secure.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Seems like this is very common. I saw this video while radiator shopping, it's changed my mind about aftermarket aluminum radiators: http://www.rockauto.com/en/moreinfo....050635&jsn=423

Re: 1987 R20 Suburban LQ4 4L80E swap
 

I've ran into the similar issues mounting my aluminum Champion radiator to my core support. None of the brackets from LMC work. I'm thinking I'm gonna get a couple pieces of aluminum tig welded to the side and bolt it to the core support.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Well that's annoying. Could you build some simple spacers out of square stock to go under the bottom mounts?

Re: 1987 R20 Suburban LQ4 4L80E swap
 

That is what my plan is now, heading to home depot this weekend to take a look around and see what I can come up with.
Glad to know this problem is not unique to me!

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Good news found a creative solution for my radiator problem.
Using the small block LMC brackets I bought, some neat aluminum spacers I found on an old sign at work, my old exhaust manifold springs, some extra radiator pads I had laying around and two small bolts.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Bad news, I got the wrong fittings for my radiator cooler lines!
Does anyone know what fittings I need to connect 6an hoses to my radiator?

Re: 1987 R20 Suburban LQ4 4L80E swap
 

I'm not sure what your radiator takes, but my stock one has inverted flare fittings. Link below.

http://m.summitracing.com/parts/AER-FBM2111

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Thanks man!
Just ordered two of those!

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Well got a little more done today, relocated the fuel regulator, mounted my overflow tank, then ran into a problem. When attaching the nipple to the radiator for the overflow tank, I found out the radiator was dented in where the filler neck is and the hole for the overflow nipple was too low and I couldn't thread it in. I pulled the neck up a little using a prybar and was able to install the nipple, but broke the weld where the filler neck meets the tank!!! In a panic I grabbed some JB weld and patched it up. Because the crack was so small and close to the filler neck, I could reach the crack from the inside and I was able to JB weld it from the inside and out. Going to wait a few days and re- apply. Wish me luck.

Good news, connected my fuel pump and turned the key and squirted fuel on the ground for a few seconds. I have been meaning to do that to make sure I have fuel comming out of my feed line. Without the engine running I am supposed to only get fuel for a few seconds right? when the engine is running it will Keep pumping correct? Figured it was a safety thing in case of an accident.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Yeah pretty sure they just prime for a few seconds unless it sees rpm.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Mine fit. Hope yours do too.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

The more I have thought about it, I just don't trust JB weld to last forever.
I am worried I would have a problem at the perfectly wrong time. Going to a shop on Monday to have it properly welded up.
My two month build estimate is gone for sure now (going into month 4 soon), no big deal, as my dad is very kind to let me use his truck until mine is done.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Nice build. You probably already covered this but what did you use for the ac Comp bracket?

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Thanks for the kind words!
used the Dirty Dingo Compressor mount:
http://www.dirtydingo.com/shop/produ...oducts_id=1418
let me know if you have any more questions.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Here is a pic of where the crack in my filler neck is (can't see the crack now because of the JB weld I foolishly tried to fix).
Taking it to a shop Monday to get welded.
also another pic of how the motor looks now. Getting close, only a few fuel lines to connect once the radiator is done!

Re: 1987 R20 Suburban LQ4 4L80E swap
 

You are close. I think in the long run you will be happy you had it welded. When you're blasting down the highway in Mississippi doing 80 when its 90 degrees out and the AC is cranked up you will know the system will hold 15 psi... Speaking of AC, what is your plan there?

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Yeah, that is what I was thinking too. It would always be on the back of my mind that it may "blow" at the wrong time. I took it yesterday to get welded. They called a little while ago and said it was ready. pressure tested and all was good. Only cost me $71!
Glad I had that done. Will pick it up tomorrow.

For A/C going with the Sadden 508 Compressor w/Dirty Dingo brackets. Keeping everything else stock, but will have some A/C hoses made once it's up and running again.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

seems like a strange place for your fuel filter/regulator. I like to keep them close to the tank to keep the return line short.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

The truck was originally a TBI equipped truck, so the hard fuel lines go to just under and behind the firewall. The feed and return lines should only be about 3-4 feet in length each from their to the regulator.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Got my Radiator back today from Four Seasons Radiator/Racing products.
They did a great job of welding my filler neck back up!

Re: 1987 R20 Suburban LQ4 4L80E swap
 

That's a good looking weld. Also side note but I like the FPR as close to the motor as possible. Less pressure drop when demand increases and long return lines don't hurt anything if properly sized.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

**update**
Funny how life seems to get in the way as soon as you start on a project like this! The last couple weeks, my two days off work have been taken up helping friends move etc...
Found some time yesterday to work on the truck a little. I got my stainless steel flexible upper radiator hose, my air intake tube, and my fuel/trans cooler lines measured and ready for cutting. After these things are cut to length, should be able to start it!
One thing I have run into, my air intake (Spectre cold air intake) puts the air filter right where my battery sits. Instead of relocating the battery, am going to cut about 5" off the intake tube/pipe. I am worried the filter is so big it may not fit when the hood is closed and my rub my new a/c compressor. If all else fails, could I just install a filter directly onto my throttle body and mount the mass air flow sensor between the filter and throttle body?

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Last night went to a friend house to use their miter saw, and I managed to get my Trans cooler and fuel lines made!
Should be able to start it on Sunday once I get these installed.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

You are probably up to speed on this, but do you have the right fittings at your trans to maintain flow? I can't recall what year they went to the different style but there is a deep fitting on the supply or return that if not used will cook your trans right away.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Thanks for the advice. Yes I believe I have the correct fittings. The one in the rear of the transmission was longer than the front.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Cool, no problem.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Well here come the Gremlins!!!

I'm now in month four of my LQ4/4L80 Swap into my 87 Suburban, and have had something strange happen. For the past 3 months everything has been fine, with all the wiring connected like it is supposed to be I could turn the key and get the motor to turn over but not start because I didn't have my fuel lines connected.
Yesterday I connected my fuel lines and went to start it for the first time and now the truck won't turn over at all. I have fuel pressure, the throttle body opens when I press the gas pedal, so I know I have power to the ecu.
I broke out my multi-meter and verified I have 12v at the starter wire coming from the ignition. When I checked for voltage at the starter solenoid with the key in the start position I get nothing. Because the truck has been down for a few months, I tried connecting some jumper cables to another car incase I had a dead battery, nothing changed. I checked for wires that my have come disconnected and the only one I found is was the power wire for my torque converter lockup. Since it was late at that point and all my tools were put up I haven't fixed that wire yet. I don't think that would have any effect on not being able to turn the motor over would it? Does the brake pedal need to be pressed to start the motor?
Because I can always get 12v from the purple ignition wire, can I just wire that directly to my starter solenoid and bypass my LS harness?
I still have the neutral safety switch intact on my steering column, that I believe the ignition wire has to go through first.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

That's weird. You have cranked it over previously? I trimmed all the old tbi circuits out of my old harness and did not use the circuit for starting supplied by Howell.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Yup cranked it over successfully about once a week for the past 3 months.
Only thing I've done since the last time I cranked it over was install the radiator and hoses, and my fuel and trans cooler lines. Thought that maybe I knocked some thing loose, so for 3 hours I checked over the wiring and found nothing.
Going to check a few more things next chance I get, if I still come up short, I'm just going to run the wire directly to the starter.

By the way, because of how far forward the motor sits, I can't get to the wires on the starter, so I'm going remove it to swap the starter wire. My question is do i need to remove the torque converter cover to remove the starter?

Thanks again for the help MTCK!

Re: 1987 R20 Suburban LQ4 4L80E swap
 

No prob. I've never had an LS motor (that I worked on) but both SBC and BBC could swap the starter and leave dust cover on the flex plate / torque converter.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Got it running today!
http://youtu.be/NFSklMgVUdQ
Still have to adjust the shift linkage and install my fan controller and it should be ready to drive soon.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Congrats it sounds great. Is your tach showing 2x the rpm? I think I recall Larry had to set his tach to 4 cylinder mode when he did his 8.1 swap. Maybe not it just didn't sound like you were reving to 5k. Nice work.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Nice to see it running Cant wait to hear how it compares to the old big block. I noticed the tach seamed really high also

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Looks and sounds great. The new gauges look right at home in there. :metal: :metal:

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Thanks guys, has been a long and expensive road, and I'm almost there. Couldn't have done it without the help of everyone on here, thanks again! Will post some more pics/videos once I have a little more to show off.
As far as the Tach, May have accidently set it to 8cyl mode instead of 4cyl mode like I'm supposed to. Sounds like an easy fix.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

It's been a while since I've worked on the truck. Taking this whole week off to wrap things up. Today I finally got my electric fans wired up, got the rest of the wiring loomed up and cleaned up. Installed new hood insulation too.
Let it run for 45 min with no overheating, leaks or any other issues.
Before I called it a day, decided to wash it for the first time in 6 months.

Re: 1987 R20 Suburban LQ4 4L80E swap
 

Picture of how it's looking now. With the new hood insulation.