LS Swap question

[kev2809]

i will be pullin the trigger this year on swapping a 99-06 nbs drivetrain in my 67 suburban. what i am wanting to do is buy a complete truck (tahoe, suburban, or yukon). what im wondering is....is there a ton of parts that get pulled from the donor truck, or just a few major components? ive been reading a ton of ls swap threads but havent come across much info of what can all swap over. for example, fuel tank and lines and components (fuel pump)...all nbs ac stuff..etc

if this stuff cant work or is not ideal, the maybe just getting the motor/trans, computer, harness, and pedal is more ideal than a whole truck.

[mongocanfly]

What's nbs mean?...
You can get by with engine,trans,ecm,wiring harness if you plan on reworking it,gas pedal if dbw,air intake..really dont need anything else..
Use your stock gas tank..use intank or inline fuel pump...
But if you have room buying a whole vehicle will give you alot of resale parts to help offset purchase price...

[kev2809]

nbs - new body style. means 99-06 body. i was thinking of using the tank of the newer truck so i can use the fuel pump and fuel lines. most threads i read usually question what lines to run. i figured if i use as much off the newer truck the easier it is?

[lyrikz]

Originally Posted by kev2809

nbs - new body style. means 99-06 body. i was thinking of using the tank of the newer truck so i can use the fuel pump and fuel lines. most threads i read usually question what lines to run. i figured if i use as much off the newer truck the easier it is?

Im gonna pretend you are using the trans of the NBS also.

Throw everything way except engine and trans. (or sell)
Buy terminator x with trans control. Installs in minutes.
Run some cheap AN fuel line and return line back to an intake pump or inline pump. Run it.

Youre overthinking it like i did. Its unbelievably easy with the Holley terminator setup.

[kipps]

I'm straying a little from my knowledge of squarebody trucks, but I'll answer this anyway.

The 99-06 tank won't fit in the 67. On newer trucks, GM widened the frame, which gave them enough space to install a fuel tank between the driveshaft and the frame rails. Your 67 will not have enough space to install that tank.

[kev2809]

exactly the stuff i need to know. i wanted to run electric fuel pump was another reason for running the stock tank...

and yes...nbs trans as well. so no driveshaft or crossmembers or wiring (other than ecm) are swapped over?

[mongocanfly]

im not sure on your trans crossmember...but on the engine id get the clamshell adapter for the engine but im betting the donor trans crossmember wont work...i reused the crossmember from my truck on the C30..
like stated above...keep your stock tank...no need to try to adapt something in place of it...a inline pump will work just fine..along with a filter/reg..but youll need a return line on the tank for it..or you can fix you tank with a intank pump
ive not seen a setup with the holly system ,but the stock controllers work fine with the right harness...that would be your call...you can mod the LS harness or buy aftermarket based on your needs...betting the driveshaft wont work either, but thats no bigger for a driveshaft shop to build or modify...id get it if for nothing else but the slip yoke..
nbs.....ok, got it now

[lyrikz]

Originally Posted by kev2809

exactly the stuff i need to know. i wanted to run electric fuel pump was another reason for running the stock tank...

and yes...nbs trans as well. so no driveshaft or crossmembers or wiring (other than ecm) are swapped over?

I dont recommend using the stock computer. That **** is dead and gone. You need someone to remove the vat system, you need a harness rework which is an absolute *****. Look at the terminator x. You can thank me later.

Driveshafts and crossmembers are going to be easily made. You can get an intake pump for pretty cheap.. Pick up a walbro 250 on ebay for a couple bucks...

[mongocanfly]

gracious...for that kind of money that holly system better work...$1300-1500
i dont know about stock comp being dead and gone...theres still quite a few on the road..
100 bucks to unlock a ecm and a new harness from psi is what i used...works just fine
i do like simple though...i guess its all in want you want to get out of it

[lyrikz]

Originally Posted by mongocanfly

gracious...for that kind of money that holly system better work...$1300-1500
i dont know about stock comp being dead and gone...theres still quite a few on the road..
100 bucks to unlock a ecm and a new harness from psi is what i used...works just fine
i do like simple though...i guess its all in want you want to get out of it

Who are you towing your vehicle to to get it unlocked/ Cost on a new wiring harness? Digital display. Its just not worth it.

[mongocanfly]

no need to tow nothing anywhere...I took the ecm to the dyno guy and he unlocked it and set it up to my needs...$100
psi harness....$549
I don't need any digital anything on mine...it runs fine as is
so $650 vs $1500..? nobrainer for my truck
and the tuner ran the truck on the dyno after I got it running and driving just to fine tune everything..
I guess its all in what you want to get out of it

[lyrikz]

Originally Posted by mongocanfly

no need to tow nothing anywhere...I took the ecm to the dyno guy and he unlocked it and set it up to my needs...$100
psi harness....$549
I don't need any digital anything on mine...it runs fine as is
so $650 vs $1500..? nobrainer for my truck
and the tuner ran the truck on the dyno after I got it running and driving just to fine tune everything..
I guess its all in what you want to get out of it

Its 1299, not 1500.
No brainer

[mongocanfly]

my fault for going by holleys site that shows a price range from $1299.95-$1499.95..and not knowing which is needed
still whatever vs $650

[lyrikz]

Originally Posted by mongocanfly

my fault for going by holleys site that shows a price range from $1299.95-$1499.95..and not knowing which is needed
still whatever vs $650

Ya, thats your 650 version. Most people dont have a dyno guy that can just run their ecu to. YOu have to tune the vehicle, holleys is self tuning mostly. Its not a 10 year old piece of equipment, its all new.

[prodjay10]

I agree with mongocanfly. He's also been a huge help getting my stuff going.

I sent my ecm to an ebay tuner in FL. Cost $70 with shipping. He deleted vats, removed emissions stuff, adjusted fan temps, and speedo settings.

I didn't buy a new harness. I reworked donor harness. It was a pain in the butt because I wasn't too familiar with the connectors or where they went, but worth it because I have a better understanding of how everything goes now. lt1swap was a huge help.

Everything works great. I did have to track down a few issues (tps, tcc solenoid, misfire) I caused during the rework and swap, but it still was worth the effort.

[kev2809]

i totally agree....one reason why i dont want to take it to a shop for this. i want to know how it works so if somethin happens i have some knowledge how its put together lol

[kev2809]

are you guys using the donor truck fuse block? thats another topic i didnt find much on...i wanted to see if anyone is junking their stock fuseblock on the kick panel and wiring everything to the donor fuse block

[mongocanfly]

are you gonna redo the factory LS harness?...if you get aftermarket harness itll come with a fuse block...the truck side fuse block ,if theres nothing wrong with it,you need to keep for the truck side...
the LS is somewhat stand alone setup..only needing constant hot, key-on hot, and some grounds to make it work and itll need its own fuseblock

[ls1nova71]

Originally Posted by kev2809

are you guys using the donor truck fuse block? thats another topic i didnt find much on...i wanted to see if anyone is junking their stock fuseblock on the kick panel and wiring everything to the donor fuse block

Are you wanting to use the whole wiring harness from the new truck for everything in your '67? If so, that will be a big undertaking, so I would just suggest you use just the engine harness and go to LT1swap.com and read up on how to mod the harness yourself. Its not incredibly hard to do, just a little time consuming, but after you are done, you will have a little better understanding of how the system works and the satisfaction of having done it yourself.

I understand the idea of the Holley system, and it is nice for someone who doesn't really understand wiring or want to mess with figuring it out, but I don't feel it is really any better than what GM made. There are millions of trucks out there having racked up hundreds of millions of miles, and still going strong, so the proof is in the numbers. I realize things have gotten better in recent years, but I may still be a little jaded having been stranded by a Holly Pro-jection unit back in the 90's! LOL! That said, never had a PCM/harness from a factory GM LS engine leave me anywhere in the last almost 20 years and couple of hundred thousand miles of driving swaps, so take that as you will.

[kev2809]

i have 2002 sierra with almost 200k miles and recently picked up a 2002 avalanche with 125k miles....which is why i want to do the ls swap. imo, this body style has the best motors chevy has made...reliabilty wise anyways. actually bought the avalanche for the swap and couldnt junk it...it was way to clean lol...now its my daily.

but anywho, i was asking about replacing the kickpanel fuse box since its so small and only has a few fuses. i figured people were pulling the donor truck too and tying it into the modern one

[ls1nova71]

Using the newer body harness in an older truck is a lot more work than I think you realize. If your '67 needs a new body harness, it would be way easier and save a bunch of time to just buy an aftermarket universal harness and rewire the truck with that. There is a lot of stuff on the newer truck that the older one wont have, so it may turn into more of a headache than you want, unless you just want to do it for fun. For instance the BCM adds a lot of wires, but does do some cool things...

[prodjay10]

Which harness would you recommend to rewire the truck? I may do that now, but I don't want to spend a bunch of money doing it. I have more time than money right now.

[mongocanfly]

...my recommendation to you would be American autowire...if your wanting to replace the entire wiring system ..I would call and talk to them...tell them what you have,,theylll recommend what you need...there are other kits also ..painless is one

[prodjay10]

No need to rewire the truck for the conversion. You just need the engine harness from the donor. If you look at lt1swap they'll show you how to remove the donor fuse box and make a tiny one with a couple relays. This is how I have mine though I'm thinking maybe its time to rewire the truck...

[kev2809]

ah ok. ya i would like a new harness but not sure if i really need one. it seems to be in decent condition...

i guess ill look more into it when i get down to getting my swap parts. im just trying to figure out how this all works. need to pull my old drivetrain and put it for sale. would def help fund some of the new parts