Doing LS Swap - I have no idea what I'm doing!

[gmc684x4]

From what I have seen there cheap for a reason cheaper connections wire guages may be smaller no heat shrink on solder joints just cheap tape

The original harness was much better made many of the ones that cost twice as much are proubly much better made i can't say how much better made as the only aftermarket harnesses i have bought are M&h factory reproduction ones which are very well made

https://m.youtube.com/watch?v=FAf1anIjxgo

[EagleChief]

Exhaust manifold question....

Will stock manifolds from a 2000 Z28 fit up and work? My engine is a 2003 LS. I found a set for sale for $45. If they will work, thought about grabbing them to use.

[Joemomma1]

Originally Posted by EagleChief

Exhaust manifold question....

Will stock manifolds from a 2000 Z28 fit up and work? My engine is a 2003 LS. I found a set for sale for $45. If they will work, thought about grabbing them to use.

Yes. I have a set I was going to run as they fit well, but preferred the smaller collector of the ls3 version. Just verify that they are indeed f body manifolds

[Joemomma1]

Originally Posted by EagleChief

I'm not an electrical wizard either. That's one reason I'm leaning toward buying a pre-made harness. I just can't fathom the thought of spending $600-$1000 (depending on set-up) on a wiring harness. I see some advertised for anywhere around $250-$300 on FB and Ebay all the time. Anything wrong with those?

Being as this is your first swap and you're not familiar with the modern components of the engine, I'd say buy a new harness or have yours reworked. When you go to fire it up and have to troubleshoot the wiring, sensors and voltages should you have trouble, the money saved is not worth it. I went with BP automotive for my first swap and am having my second harness reworked. My third will use the whole harness and fuse box as is from the donor.

Don't go with the Chinese harnesses as they can get you by but you are not there yet to troubleshoot or repair them should you need to. You're already half the cost of a quality harness.

[EagleChief]

Originally Posted by Joemomma1

Being as this is your first swap and you're not familiar with the modern components of the engine, I'd say buy a new harness or have yours reworked. When you go to fire it up and have to troubleshoot the wiring, sensors and voltages should you have trouble, the money saved is not worth it. I went with BP automotive for my first swap and am having my second harness reworked. My third will use the whole harness and fuse box as is from the donor.

Don't go with the Chinese harnesses as they can get you by but you are not there yet to troubleshoot or repair them should you need to. You're already half the cost of a quality harness.

I'm going to talk to a couple shops local to me that specialize in LS tuning and wiring. I'll get some prices from them to see if they have harnesses already made up, or, use mine to cut down and use.

[Pitpig]

Probably already mentioned, but stock harness rework is simple. Just flow LT1swap instructions (with pictures!!) Your basically just removing the stuff you don’t need. To me the biggest benefit was a better appreciation of what each circuit does. They’re not pretty, but they’re cheap. What have you got to lose?

[EagleChief]

Originally Posted by Pitpig

Probably already mentioned, but stock harness rework is simple. Just flow LT1swap instructions (with pictures!!) Your basically just removing the stuff you don’t need. To me the biggest benefit was a better appreciation of what each circuit does. They’re not pretty, but they’re cheap. What have you got to lose?

I have looked through the walk-thru over at LT1swap. Looks like a big bunch of spaghetti! Fear of cutting the wrong wires, or messing something up is the problem holding me back, I think. But, my biggest obstacle is time. Going through the wiring seems like it would take several hours to go through. My time in the garage, currently, is probably 20-30 minutes at a time - IF I'm lucky.

[EagleChief]

Another question I have...

Engine placement. Is that a trial and error thing? I have ICT adapter plates and stock '71 motor mounts. The adapter plates have 4 mounting points to position the motor forward/back. Is there a way I can get some measurements on the truck to give me an idea of where to put the mounts? Or, will I just have to drop the motor in, try it out, and then adjust the mounts as needed?

[Thealien]

Originally Posted by EagleChief

Another question I have...

Engine placement. Is that a trial and error thing? I have ICT adapter plates and stock '71 motor mounts. The adapter plates have 4 mounting points to position the motor forward/back. Is there a way I can get some measurements on the truck to give me an idea of where to put the mounts? Or, will I just have to drop the motor in, try it out, and then adjust the mounts as needed?

I have the same ICT plates with the four holes. I wanted room behind the engine and we originally put it in the forward holes. There was a lot of space behind the engine and not much between the water pump and the radiator fans. We ended up going to the second set of holes from the back moving the engine back about 1 3/4”. The body is not back on yet So I am not sure how much clearance is left behind the Engine.

So I guess to answer your question it is trial and error. If you go to the I CT website it says what each set of holes does. I believe the first hole is .1” forward the second hole is .6” I am not sure but the third set of holes it’s like 1.7” or 1.8”. Off the top of my head I can’t remember what the forward set of holes measurement is but it’s easy to find on their website.

[Joemomma1]

Originally Posted by EagleChief

I have looked through the walk-thru over at LT1swap. Looks like a big bunch of spaghetti! Fear of cutting the wrong wires, or messing something up is the problem holding me back, I think. But, my biggest obstacle is time. Going through the wiring seems like it would take several hours to go through. My time in the garage, currently, is probably 20-30 minutes at a time - IF I'm lucky.

Then don't do it. Send that work out and focus on something else to keep the project moving. Anything that can be completed in the time you have is still progress.

Originally Posted by EagleChief

Another question I have...

Engine placement. Is that a trial and error thing? I have ICT adapter plates and stock '71 motor mounts. The adapter plates have 4 mounting points to position the motor forward/back. Is there a way I can get some measurements on the truck to give me an idea of where to put the mounts? Or, will I just have to drop the motor in, try it out, and then adjust the mounts as needed?

They should have given you or have some kind of info on what mounting holes will place the engine relative to the factory positioning. This is why I went with slider plates rather than those plate types with the static positions. I just dropped mine in with the transmission and adjusted from there. 30 minutes should be enough time to choose a position, drop it in and see where it sits. Adjust on your next chance.

[Pitpig]

Eagle chief: the wiring is tedious, cutting the wrong wire not much of a concern, you pull the pins out of the connector and then the wire from the loom. Would be hard todo it 20 minutes at a time though!

[biketopia]

If you want to save the couple hundred of dollars on the harness you can find the time to make it work. I understand you have a new born but maybe the engine swap needs to be shelfed for a little, adjust your time frame, or stop getting hung up on wiring, that should be pretty much your last step. Get the engine in, trans in, figure out exhaust, plumbing, sensor placement, fuel system, shifter linkage, PS hook up, etc, then worry about wiring in a few months when maybe the kid is sleeping a little more normally, and you can spend an hour at a time on the harness. Plenty of people have dove into a harness with zero automotive electrical knowledge, its not hard, just takes a little time. Get a 4x8 sheet of ply wood and lay the harness out on it so it's not just a jumbled mess of wires in a box, then you can ID the pins you need and don't, take your removal tool and slide the wire out, throw it in a box for spare wires and pins and move on to the next. It's pretty straight forward when you let your self take your time and don't try to bite off more than you can chew. It sounds like you're giving yourself an "overhauling" or TV style time line, that's just flat unrealistic, especially given the fact you can't work on the truck full time. Make your self a legitimate list of things to do and conquer them one step at a time. The board is always here to help and answer questions so you can have the info you need before you walk into the garage not after.

[jjzepplin]

I had a 1999 Trans Am and the stock manifolds did not fit. Headers might have. I went with Speed Engineering Headers and they needed some work too. I have this in a 72 Blazer with ICT mounts and all the way back so the Stock oil Pan would clear. If you choose to purchase a harness, someone on here will snatch up the stock unit.

[EagleChief]

Originally Posted by Thealien

I have the same ICT plates with the four holes. I wanted room behind the engine and we originally put it in the forward holes. There was a lot of space behind the engine and not much between the water pump and the radiator fans. We ended up going to the second set of holes from the back moving the engine back about 1 3/4”. The body is not back on yet So I am not sure how much clearance is left behind the Engine.

So I guess to answer your question it is trial and error. If you go to the I CT website it says what each set of holes does. I believe the first hole is .1” forward the second hole is .6” I am not sure but the third set of holes it’s like 1.7” or 1.8”. Off the top of my head I can’t remember what the forward set of holes measurement is but it’s easy to find on their website.

Just went back to the ICT site to see what I could find. They actually have a video posted that says the front-most set of holes are the closest to factory small block location. I didn't see that video when I was on their site before. But, for future reference, or anyone else that wants to know, here is what they say:
"There are 4 positions for maximum adjustment of engine (from .100" forward of OEM bellhousing position [due to bolt interference, OEM location is not possible for any brand of flat style swap plates] ~forward most position shown in photos~, Secondary positions are: .600", 1.86", and 2.36" engine moved forward)

These swap plates will shift the crankshaft centerline up .177" above factory small block location."

I currently have mine set at the #2 position. I may move them up, but I wonder if it will make a difference that my truck did not have the factory transmission. Trial and error it will be.

[EagleChief]

Originally Posted by biketopia

If you want to save the couple hundred of dollars on the harness you can find the time to make it work. I understand you have a new born but maybe the engine swap needs to be shelfed for a little, adjust your time frame, or stop getting hung up on wiring, that should be pretty much your last step. Get the engine in, trans in, figure out exhaust, plumbing, sensor placement, fuel system, shifter linkage, PS hook up, etc, then worry about wiring in a few months when maybe the kid is sleeping a little more normally, and you can spend an hour at a time on the harness. Plenty of people have dove into a harness with zero automotive electrical knowledge, its not hard, just takes a little time. Get a 4x8 sheet of ply wood and lay the harness out on it so it's not just a jumbled mess of wires in a box, then you can ID the pins you need and don't, take your removal tool and slide the wire out, throw it in a box for spare wires and pins and move on to the next. It's pretty straight forward when you let your self take your time and don't try to bite off more than you can chew. It sounds like you're giving yourself an "overhauling" or TV style time line, that's just flat unrealistic, especially given the fact you can't work on the truck full time. Make your self a legitimate list of things to do and conquer them one step at a time. The board is always here to help and answer questions so you can have the info you need before you walk into the garage not after.

I definitely don't have a TV style timeline... I know better than that. I mean, my motor has been sitting on the garage floor for almost 2 months, so definitely not in a hurry. I'm just trying to make a list in my head and have an idea of what I need to look forward to. I like the idea of not worrying about the harness until after everything is mounted and in place.

[EagleChief]

So, fun story...

Friday evening after the kids were asleep, I went out to the garage to try and extract the stuck exhaust manifold bolts. Center drilled the first one (flush with head), drilled a slightly larger hole. Then tried a slightly larger drill bit - NOPE! That bit snagged on the edge of the hole, and, SNAP!! Broke it in to 3 pieces! So, I get the extractor out. Work it into the bolt... won't work. I try it a few times - back it out, put the extractor back in, try it, back it out, etc. Nothing. Spray it down with PB Blaster for the 3rd or 4th time, try it again. SNAP! Busted the bolt extractor right at the head, flush with the bolt!!!! WTH?!! After that, I didn't even try the other bolts. Off to bed I went, defeated... for the time being.

I'll be back at it. I have some new bits ordered. Watched a couple of "how to" videos to see if I can get it out of there. If not, guess I'll have to pull the heads (don't want to do), and bring them into my shop to get machined. To Be Continued...

[biketopia]

I understand the "no" time line, my truck has been off the road for like 5, going on 6 years, and has been in pieces for the better part of 3 haha. Making a big written list (I do them in the notes section of my phone so I can look and ad when things pop into my brain), like engine, body, exhaust, plumbing, then smaller lists like brake lines, fuel lines, coolant, trans cooler, etch will help you out tremendously. Its super daunting, but little by little you start to make progress when you can and then you look back your list that keeps getting smaller and BAM, your driving the truck haha.

That really sucks about the bolt, do you know any one with a small 110V MIG welder they can bring over, it's a super fast job to tack onto the bolt and then weld a nut on and back it right out. Especially with it out of the truck, would honestly take 15 min. If I was near you I'd gladly swing by, but VA isn't near OK.

[EagleChief]

Originally Posted by biketopia

I understand the "no" time line, my truck has been off the road for like 5, going on 6 years, and has been in pieces for the better part of 3 haha. Making a big written list (I do them in the notes section of my phone so I can look and ad when things pop into my brain), like engine, body, exhaust, plumbing, then smaller lists like brake lines, fuel lines, coolant, trans cooler, etch will help you out tremendously. Its super daunting, but little by little you start to make progress when you can and then you look back your list that keeps getting smaller and BAM, your driving the truck haha.

That really sucks about the bolt, do you know any one with a small 110V MIG welder they can bring over, it's a super fast job to tack onto the bolt and then weld a nut on and back it right out. Especially with it out of the truck, would honestly take 15 min. If I was near you I'd gladly swing by, but VA isn't near OK.

Well, 2 of the bolts are flush with the head, or down inside the head a little bit... 1/8" or so. The other 2, that would probably work. I believe my neighbor has a small welder. I'll have to hit him up and see if he has it in is garage.

[LS short box]

The bad (or good) is that those extractors are super hard metal. You won't be able to drill them out with common drill bit. I know its not fun but I'd pull the heads and send them to a machine shop for repair..

[Thealien]

Originally Posted by EagleChief

Well, 2 of the bolts are flush with the head, or down inside the head a little bit... 1/8" or so. The other 2, that would probably work. I believe my neighbor has a small welder. I'll have to hit him up and see if he has it in is garage.

The welder trick works great. Especially on aluminum heads. And welding the nut onto the bolt even though it’s a little down in the hole heats up the bolt and now with the nut it usually comes out pretty easily. Good luck.

[Captainfab]

I never bother trying an easy-out unless I know the broken bolt is not seized up. They always just snap off. Welding a nut over the broken bolt is the best way to get them out. You need a welder big enough to burn into the broken bolt.

[v30crewcab]

the bolts are locktited in, and require heat to get them to come loose. only way I've gotten them to come out.

[EagleChief]

So, I'm still looking for some exhaust manifolds. Found a couple of sets of interest. A set from a 2017 6.2L Camaro, and also a set from a 6.2L LS3 Corvette (not sure of the year, yet).

Anyone know if those will work out for me?

EDIT**** Well, found out the Camaro set is an LT engine, so that's out.

**EDIT 2** Buying the Corvette manifolds. I'll see if those will work. I know they'll bolt up to the engine, just need to see if they'll work when installed. ��

[ls1nova71]

Originally Posted by EagleChief

So, I'm still looking for some exhaust manifolds. Found a couple of sets of interest. A set from a 2017 6.2L Camaro, and also a set from a 6.2L LS3 Corvette (not sure of the year, yet).

Anyone know if those will work out for me?

EDIT**** Well, found out the Camaro set is an LT engine, so that's out.

**EDIT 2** Buying the Corvette manifolds. I'll see if those will work. I know they'll bolt up to the engine, just need to see if they'll work when installed. ��

Do you have a pic of the Corvette manifolds? Generally Vette manifolds don't fit in most swaps. You would be better off with TBSS, Gen5 Camaro or Pontiac G8 manifolds.

[LS short box]

Just FYI. I'm working on a 1980 Camaro project with a 6.2/4L60E swap. I typically use Howell harness and computer package. I was a bit shocked to learn their lead times are 4-6 weeks. So I called Speartech, I've used them in the past also. Their lead times are 11-13 weeks! In years past it was 2-3 weeks. So plan ahead.