Thread: My 1984 K10 - LM7 swap!!

Originally Posted by BillBoost37

Pretty sure new englanders are more car dumb than a lot of the country. The things I see around here.

You might have a point there. When I lived in Michigan, it seemed like people had greater basic knowledge of automobiles. Maybe it's in our/their DNA. Not so much here in Tucson...

Brandon, are you going to be able to strap the stand down to make it sturdy enough? The engine start up stands I've seen at shops are rather large.

I'll fab up some outriggers bolted to the engine block depending on what I have in the garage. Might have to make a trip to Industrial Metal Supply next weekend. I did test fire the LQ4 without any bracing, but I left the hoist connected incase it decided to get rowdy. I remember it being fairly stable. With the addition of some support, this should be mostly safe.

Originally Posted by idrivejunk

Imagine the things we see living in Arkansas, think about that one.

I've seen a Cali forum dude crank up a Cobra Jet 428 breifly, no throttle whipping just low gentle off-idle revs... with some tubular lateral extensions clamped in place. Hows the saying go... Its not standing on a cliff thats dangerous, its not watching your step while you're there!

Exactly. I think a set of supports will be good. When these motors fire, they wind up to about 1000 rpms right away, then settle into a nice 400 rpm idle. If I make it past the initial startup without dumping it, we should be good for a couple mild throttle blips.

Brandon, I like your harness-weeding pics a lot better than the maximum chaos spaghetti plate images this one ol rodder guy posts on another forum. We go back and forth making each other puke, me by rust porn and him by those confounded messes of wire.

LOL. This harness should actually end up being very clean. It's like 95% stock. I ordered up some more of the TESA fabric harness tape to take it just one notch above factory, but without being too fancy. I debated very briefly, the idea of doing a wire tuck, but I really like the functionality and serviceability of the stock harness layout. I should also have enough hood clearance in the K10 to use the engine cover and hide most of it.

EGR block off came today. Probably be the only emissions system I delete since it has to pass the sniffer. I'm even leaving in the post cat O2's



I really like the black. Almost disappears.



More loom work.







There's probably about one more evenings worth of work on looming pigtails before I call it good enough for now. I'm not going to loom the larger harness sections until it's in the truck. I still need to add wires for things like the OBDII plug, MIL, tach output, TCC/brake switch, 4wd signal switch etc. And even though I'm not running AC or electric fans right now, I'm going to run the control wires.

the look on the guys face at inspection,,,,its gonna be priceless. what you mean its obd2? lmao

We'll see. Those AZDEQ guys (and gals) don't get excited about much. Just minimum wage zombies going through the motions. Not trying to put anybody down. I just want to shame them all into quitting! That reminds me though... I need to snag the OBDII plug out of the Yukon.

Well, I got absolutely nothing done on the engine. Had to take the boy to soccer practice. yay. I did get some parts though. Right side PCV hose was badly cracked. Surely would have been a vacuum leak.



New hose was like $9, so I went for it.



Also chopped one plug off the old Yukon harness. I'll use this to make a break in the K10 harness for all the things I mentioned earlier that need to feed into the cab. (OBDII plug, MIL, tach output, TCC/brake switch...)

Nice amount of stuff you have gotten done in short time Brandon. As always a great and meticulous approach.

I likely missed it, how are you planning to add in all those items in the cab? Are you able to tap into the existing K10 brake switch? Will you add a MIL light or use one of the lights that were down to the left in the dash (going off memory I think there was brake and something else).

Originally Posted by BillBoost37

Nice amount of stuff you have gotten done in short time Brandon. As always a great and meticulous approach.

Thank you sir!

I likely missed it, how are you planning to add in all those items in the cab? Are you able to tap into the existing K10 brake switch? Will you add a MIL light or use one of the lights that were down to the left in the dash (going off memory I think there was brake and something else).

Honestly, I don't have anything fully figured out yet. Just mapping it out in my head right now. I'll probably tap into the brake light switch for the TCC signal. For the MIL, I'll likely use the "CHOKE" light. Can't remember what the other lights in the cluster are, but I know for certain the choke light will be obsolete after the swap. Everything else I'll figure out on the fly.



I want the Yukon out of here before I rip the K10 apart, so it needs to go SOON. Pulled off the last couple things I think I'll need. Am I forgetting anything? (Trans cooler and PS cooler not pictured)



Got some more parts today. Biggest thing was the headers, but I didn't even unwrap them. Not going to mount them until the better header bolts I ordered arrive. Also got the coolant temp sensor pigtail. I want to keep all the factory gauges working. Once that's soldered in, I can loom that section of harness.

Things to consider pulling:
Fuel pump. There's a mechanical pump on the K10, right.
Brake switch, just in case it's different enough of a signal that you might want to add it in.
Throttle cable
4wd switch

That's all I can think of at the moment. The second it's gone...you'll find something.

Originally Posted by BillBoost37

Things to consider pulling:
Fuel pump. There's a mechanical pump on the K10, right.
Brake switch, just in case it's different enough of a signal that you might want to add it in.
Throttle cable
4wd switch

That's all I can think of at the moment. The second it's gone...you'll find something.

throttle cable? gas pedal assembly you must mean and all its wiring.

Originally Posted by BillBoost37

Things to consider pulling:
Fuel pump. There's a mechanical pump on the K10, right.

Correct. I'll probably do a stock in tank pump from a late 80's TBI truck. Supposed to be a direct bolt in to the old tank. Super easy and very cost effective. Just need to run power and ground to the pump.

Brake switch, just in case it's different enough of a signal that you might want to add it in.

Good thinking. I'll snag that.

Throttle cable

Yup. Got that!

4wd switch

You talking about the push button dealey in the dash?

That's all I can think of at the moment. The second it's gone...you'll find something.

That's exactly what happened with the 2500HD that I used for the S10. The week after I sold it I went "Ugh, I should have grabbed the driveshaft!"

Originally Posted by Scottydoggs

throttle cable? gas pedal assembly you must mean and all its wiring.

No, he's right. Just the cable. It's a DBC throttle body. The ends on the engine side are different for carb vs throttle body. Carb cable has kind of an eyelet with retaining clip. Throttle body has a knarp. Pedal side is exactly the same. Should be a simple swap. Best part is the $0 cost!

i thought for sure they were dbw by then, i know 03 was.

They started DBW in 2002 on like some suburbans and yukon SLT/Denali packages, then all of 2003+ went to the P59 computer with DBW.

Anything 1999-2001 is pretty much only cable and the silverado/sierra was cable untill 2002 then the switch over in 2003 like the rest.

Corvettes were DBW way back in 1997/1998 with the first LS1 cars.

Hmmm. I didn't know that. My '02 LQ4 was DBC. I thought they ran the DBW TB's way later. Probably because I'm poor and I've only ever seen the older junk.

Got my fancy $7 fuel rail gauge fitting. Hydraulic fittings are great!



Just need my $20 Jegs gauge. I really like knowing the pressure at the rail.



Did a little housekeeping. Getting ready for something...



LM7 build is on pause for a week or two. Building a 4L60e for a buddy.

Carb the darn thing!
Kidding, I just heard poor people and junk so I raised my head. Drive by wire is like smiling in a photograph, evil. Haha. I got to thinking about my friends' rides and dang...can only think of one other person still running a carb. I must have been asleep when EFI happened.

I'd like to say.. I was paying attention.

Will you be running that FP inside the cab for real time info and doing the sensor that will feed HPT? You know you want to.

BTW, keep the driveshaft! On the K10, if you have the other side of the bed cut for a gas tank, you know all you have to do is flip the brackets on a stock tank and you can run two? I did on my 75, Dad had gotten a newer bed and the fuel door was on the opposite side. The place cut the spot for the stock screw on cap. Having bought a parts truck, I chose to add the tank with a electric change over valve and hooked up the gauge to read which ever tank was feeding the engine.

This thread has me wanting to build a truck

Heavy duty trucks, those being 2500 and 3500 were still cable driven from 1999-2002 and 2003 was DBW.

If you want to get really technical they still used cable throttle bodies all the way to 2005 in the heavy duty vans. The express and savana vans stayed cable for much longer and those computers had special IAC drivers on the circuit board. Lots of people will actually switch back to cable if there drive by wire truck had a computer with the drivers built into the computer board.

Originally Posted by idrivejunk

Carb the darn thing!

LOL! I'm doing all this work specifically to get away from a carburetor!

Kidding, I just heard poor people and junk so I raised my head. Drive by wire is like smiling in a photograph, evil. Haha. I got to thinking about my friends' rides and dang...can only think of one other person still running a carb. I must have been asleep when EFI happened.

I understand why some people hang on to their carbs. Stick with what you know. I'm not mad at a guy for having a shiney Edelbrock 4bbl and air gap intake on his/her crate 350. HOWEVER, if you put a carb on an LS motor, I feel like you just traded a touch screen tablet for an abacus. (I can hear some crusty old guy in the back yelling "An abacus never runs out of battery!" Thanks old guy....)

Originally Posted by BillBoost37

Will you be running that FP inside the cab for real time info and doing the sensor that will feed HPT? You know you want to.

Now that you say that, I DO WANT TO! And I might do something like that in the future. Right now, it'll just be the analog gauge on the rail. On the next build though...

BTW, keep the driveshaft! On the K10, if you have the other side of the bed cut for a gas tank, you know all you have to do is flip the brackets on a stock tank and you can run two? I did on my 75, Dad had gotten a newer bed and the fuel door was on the opposite side. The place cut the spot for the stock screw on cap. Having bought a parts truck, I chose to add the tank with a electric change over valve and hooked up the gauge to read which ever tank was feeding the engine.

LOL. Yeah, I got the driveshaft. Unfortunately, the right bedside is not cut for a fuel door. There is the bump in the floor for the hose clearance though.

This thread has me wanting to build a truck

I'd be really interested to see that build. I really like the way you approach and solve problems.

Originally Posted by Fivefingerdeathpunch

If you want to get really technical they still used cable throttle bodies all the way to 2005 in the heavy duty vans. The express and savana vans stayed cable for much longer and those computers had special IAC drivers on the circuit board. Lots of people will actually switch back to cable if there drive by wire truck had a computer with the drivers built into the computer board.

Isn't the "Holy grail" PCM, a DBC (with IAC drivers), 2 (maybe 3) bar, and flex enabled? I haven't played with boost or flex yet, so I'm not really up to speed on all the different PCM configurations.


Got my header bolts and 3 wire coolant temp sensor today.



Promptly mounted the headers which, I'll admit, was a waste of time and space but I love that look!



Okay. Everything I had on order has now arrived. NOW the build is on hold.

If the early P01 computer had flex fuel with IAC drivers the only known OS that works is from like a 2002 Tahoe and I thought those only supported 2 bar OS upgrades.

The later DBC P59 computer from like a van can have 3 bar OS upgrades but the resolution on the VE table is horrible. Instead of going up by 5kpa or even 10kpa values they are 20kpa, which really sucks for fine tuning. You'll have a VE that goes from 30kpa to 310kpa going by 20 each, so 30,50,70,90,110 etc etc and you miss everything in between. You can still make it smooth but it's not as precise. On some operating systems it was better to stick with a 2 bar OS because the 3 bar made it worse to be super accurate.


Were those manifold bolts cheap?

I always buy them from Napa because they are such a good deal there. I think it's 10 bucks for the box of 12.

Originally Posted by Fivefingerdeathpunch

The later DBC P59 computer from like a van can have 3 bar OS upgrades but the resolution on the VE table is horrible.

That must be what I'm remembering. I didn't know about the poor resolution. I'm going to get into all that minutia on the next build.

Were those manifold bolts cheap?

I always buy them from Napa because they are such a good deal there. I think it's 10 bucks for the box of 12.

Exactly. $10 shipped from ICT billet. I figured pretty much anything would be better than what comes with the headers. They included studs with nuts and they looked really cheesy.

You fire it up yet?