LS Swap 70c10 Need help

[Project_70']

Okay to start off with i am sorry if this has already been talked about here, but i am new to using forums, i created this account last year and never got around to asking but anyways to my questions and concerns.
I am in the process of trying to find a 5.3 LS for my truck and i've been doing a lot of research the past week or so and i have some concerns that i haven yet been able to clear. My first concern is on the transmission linkage. I plan on using the stock TH350(Financial reasons) that came with the 350/350 combo from the factory. now when i mate the TH350 to the 5.3 will my stock linkage still hook up and work? I will be using Dirty Dingo mounts that are adjustable for this reason, in case i have to push it forward or backward some. My Second concern is the drive shaft. Will the stock fit? Will i have to have a custom one made? Also i'm not planning to use A/C But i want to use P/S. Will the power steering pumps to these late model style trucks work with the older style gear box? Sorry if these questions can be easily answered somewhere else, if so someone please link me. i've tried my best on the web to find some info on these topics but it seems every time i find a swap on one of these types of trucks they arent very thorough on these specific topics. any help is appreciated! Thanks!

[Heavymetl]

1) Transmission linkage is super easy. You have two options. Use engine slider mounts and make sure the transmission stays in the same position longitudinally, or if it does not, the Lokar universal shift rod fits excellent and can be installed in about 15 minutes. I have the stock column shift and use the Lokar rod with the 4L80E.

2) If your transmission stays in the stock location, no driveshaft mods needed. Otherwise, a custom shaft would need to be build.

3) Power steering is also simple, you can simply swap the fitting from the back of your current pump to the newer pump on the LS. I even re used the stock lines after just a little bending for clearance.

Hope this helps and good luck.

[Project_70']

Appreciate the quick reply, and yes that helps a lot! wasn't even expecting a reply to be honest lol. I am still a little Foggy on the fuel delivery system, i have a buddy using a walbro 255 on his 83 c10 with a 6.0 but cant quite get a hold of him to ask him some questions. would be great to get the fuel system mapped out! Also i see your signature says your boosted, somewhere down the road i hope to do the same maybe you can shed some light on your build? or do you have a link? Would love to see it!

[Heavymetl]

Sure, plenty of pics here. It's a bit awkward sharing this link (I'm not self promoting) but they are nice pics.

https://theblock.com/news/nate-hines...d-lm7-1970-c10

The walbro 255 is great, especially in tank. I would not recommend that with the in cab tank though, too noisy. With these truck a rear fuel cell just works really well.

This forum has an entire LS swap section, be sure to check it out

[Project_70']

Appreciate the help man! And Wow just kinda had my mind blown there for a sec...ive seen your truck all over my Instagram Feed before and i've wanted something similar ever since! Perfect build my friend. Love the "Patina" look. And i will im trying to get used to the forum and get a feel for things, so far its been great help!

[The Chainsaw]

I agree that the walbro inline 255 is a little loud, but my brother in law has his mounted underneath the cab and it isn't too bad. You can hear it while driving, but the exhaust is extremely quiet.

I run 2 walbro inline 255 pumps on my turbo 6.0 in my chevelle. They work great, and haven't had any problems even though they are mounted above the pickup in the tank.

Holley also makes adapter plates that put the back of the motor in the same spot as the stock motor. No changes needed behind the motor. Heard great things about the dirty dingo mounts as well.

There are a few aftermarket dished flexplates you can use with crank spacers for the older transmissions/converters, but I use a stock flexplate/spacer from a 6.0/4L80E combo that bolts right up. Haven't had any issues with it even with transbrake launches @3900lbs.

[Heavymetl]

Originally Posted by Project_70'

Appreciate the help man! And Wow just kinda had my mind blown there for a sec...ive seen your truck all over my Instagram Feed before and i've wanted something similar ever since! Perfect build my friend. Love the "Patina" look. And i will im trying to get used to the forum and get a feel for things, so far its been great help!

Lol, the "internet fame" was the last thing I ever expected. I just wanted a fun truck for parts hauling and sunmer daily driving. It's been great and I put over 8000 miles on it last year.

This forum is a tremendous resource, use the search function and keep browsing. I believe message boards such as this have done more for the hobby than anything before.

[Hart_Rod]

If you go with a drive by wire pedal, check out my adapter bracket:

http://67-72chevytrucks.com/vboard/s...d.php?t=651123

[Kennuck]

I know you are trying to save money by using the TH350 but your going to need a few things to use it. The engine needs a speed signal to operate properly so you are going to have to buy an electronic speed sensor to make it work. Guys will tell you, you can do away with the speed sensor but this generally results in poor fuel economy and driveability problems. I know there are also spacing differences between the torque converter and flex plate that may cause you problems?

Often you can buy an engine and trans combo for little extra than the engine alone and save all these hassles and gain overdrive. The 4L60E uses the same output shaft spline as the TH350 and with proper engine placement you can use your stock driveshaft. The total cost is likely a wash and you gain O.D.

[The Chainsaw]

Originally Posted by Kennuck

I know you are trying to save money by using the TH350 but your going to need a few things to use it. The engine needs a speed signal to operate properly so you are going to have to buy an electronic speed sensor to make it work. Guys will tell you, you can do away with the speed sensor but this generally results in poor fuel economy and driveability problems. I know there are also spacing differences between the torque converter and flex plate that may cause you problems?

Often you can buy an engine and trans combo for little extra than the engine alone and save all these hassles and gain overdrive. The 4L60E uses the same output shaft spline as the TH350 and with proper engine placement you can use your stock driveshaft. The total cost is likely a wash and you gain O.D.

I haven't seen any fuel economy or driveability problems running the older transmissions other than the gear ratio. Been there and done that one with both stock ECU's and Holley's EFI. Either one will adjust A/F ratio depending on so many factors, that I never noticed any difference. Just my experience.

Although I have eaten up a few thrust bearings with my Hughes Th400 because of converter charge pressure+Boost.

[Project_70']

Posting Below..

Well ive been looking and i found this, was wondering if maybe i could get some feedback? i called the guy and he is an older gentleman with a history of selling these ls based engines. he said the truck was wrecked into the back of a dump truck? said it sustained some good damage to the front end but missed the engine totally(as seen in the pics on the post) and belonged to an area police dept.(Denton) and he bought it at an auction. I asked if i could crank it and hear it run, he said it wont turn over, MIL light comes on and odometer doesn't come on. i may run down and pick it up and take a shot but wanted some second opinions before i go and possibly blow a 1k bill on something that could cost me in the end.
also he mentioned he has about 4 people so far that have called and are trying to go after it but no ones showed. said he has 2 coming for it this weekend and first to give him money gets it.

https://dallas.craigslist.org/ftw/pts/5418497820.html

[ls1nova71]

Originally Posted by Project_70'

Posting Below..

Well ive been looking and i found this, was wondering if maybe i could get some feedback? i called the guy and he is an older gentleman with a history of selling these ls based engines. he said the truck was wrecked into the back of a dump truck? said it sustained some good damage to the front end but missed the engine totally(as seen in the pics on the post) and belonged to an area police dept.(Denton) and he bought it at an auction. I asked if i could crank it and hear it run, he said it wont turn over, MIL light comes on and odometer doesn't come on. i may run down and pick it up and take a shot but wanted some second opinions before i go and possibly blow a 1k bill on something that could cost me in the end.
also he mentioned he has about 4 people so far that have called and are trying to go after it but no ones showed. said he has 2 coming for it this weekend and first to give him money gets it.

https://dallas.craigslist.org/ftw/pts/5418497820.html

Doesn't sound like a bad deal to me, but that's if it's a 2wd. If it's a 4wd, then the trans won't do you much good, assuming you're building a 2wd since you didn't mention it being a 4x4. I agree with the other poster about just getting a 4l60e to go with it, better off in the long run. You'll get a little better fuel mileage with the overdrive, and like he said, you need a VSS. Some people say you don't, but more often than not, not having one can cause stalling problems when coming to a stop.

I would look that truck over good, you can usually get an idea of how many miles are on a truck by the condition of it, or at least be able to tell if it was properly maintained. If it's clean, it could be lower mileage or was owned by someone who cared about it. If it's a ragged out pile, then it probably has a boat load of miles and if it doesn't, it's probably never had an oil change and you don't want that. A 100k plus mile LS engine is still a good foundation, since these engines are built well so don't go only on miles.

[Project_70']

Originally Posted by ls1nova71

Doesn't sound like a bad deal to me, but that's if it's a 2wd. If it's a 4wd, then the trans won't do you much good, assuming you're building a 2wd since you didn't mention it being a 4x4. I agree with the other poster about just getting a 4l60e to go with it, better off in the long run. You'll get a little better fuel mileage with the overdrive, and like he said, you need a VSS. Some people say you don't, but more often than not, not having one can cause stalling problems when coming to a stop.

I would look that truck over good, you can usually get an idea of how many miles are on a truck by the condition of it, or at least be able to tell if it was properly maintained. If it's clean, it could be lower mileage or was owned by someone who cared about it. If it's a ragged out pile, then it probably has a boat load of miles and if it doesn't, it's probably never had an oil change and you don't want that. A 100k plus mile LS engine is still a good foundation, since these engines are built well so don't go only on miles.

Thanks man i'll definitely look it over as best as i can if i go after it. Also im guessing that the trucks check engine light is on and wont do anything because it was wrecked? could i be able and take a flashed pcm down there and somehow try and start it? theres a vid on youtube showing how to 2 wire start it but it needs a flashed pcm with vats removed.

[F.A.A.benny]

1k seems reasonable but I would like to hear it run unless I can get some kind of warranty. But you are only going to get that from a salvage yard, if that.

[kenhoef]

Hello, Just checking in first time, I have a 70 C10 custom long bed, trying to decide to swap out tired and abused 350 (not original) for a 350/383 or go with an LS swap. I would like to retain the AC and all other accessories. I welcome any feedback...

[Project_70']

Originally Posted by kenhoef

Hello, Just checking in first time, I have a 70 C10 custom long bed, trying to decide to swap out tired and abused 350 (not original) for a 350/383 or go with an LS swap. I would like to retain the AC and all other accessories. I welcome any feedback...

welcome i am new here too lol and well same truck and sorta same situation for me but i put together my costs for building an old conventional engine(355/TH350 mild build) to just doing a swap and price was pretty much close to the same. So i figured well for the same price, i mind as well LS swap it, but came across a lot of concerns that have been mostly cleared on this thread. Gaining Fuel Injection, along with modern technology and performance i figured it was worth it. Also as i was told in the thread before there is a part of the forum dedicated to LS swaps also full of helpful info.

[The Chainsaw]

I can tell you without a doubt that it is absolutely not true that you need a VSS sensor to avoid stalling coming to a stop. That is almost 100% IAC hold position and decay rate.

The overdrive is very nice and definitely worth it for the right price, but there aren't any tuning issues without a VSS. There are hundreds of people doing it with both stock ECU's and aftermarket. The stock ECU is a bit trickier, but not a problem with a competent tuner.

[Project_70']

Originally Posted by The Chainsaw

I can tell you without a doubt that it is absolutely not true that you need a VSS sensor to avoid stalling coming to a stop. That is almost 100% IAC hold position and decay rate.

The overdrive is very nice and definitely worth it for the right price, but there aren't any tuning issues without a VSS. There are hundreds of people doing it with both stock ECU's and aftermarket. The stock ECU is a bit trickier, but not a problem with a competent tuner.

Really appreciate the feedback buddy. Here is the posting for what i am trying to get: https://dallas.craigslist.org/ftw/pts/5418497820.html
Its altogether but if i have problems with the tranny and clearance problems then ill go with the th350 set up instead. and it makes since for it to be the IAC for stalling problems or things of that matter. the VSS on the other hand would be used to determine the speed on the input shaft of the transmission i am assuming? still learning these things at the moment lol also a fellow friend on the forum here says he can reprogram my PCM and make sure everything checks out good.(he has bascially same truck and set up im going with) so we'll see how things go. but there are still a few hiccups im trying to get figured out such as, speedo hookup, tach, odometer, and small things im sure ill run into. speaking of aftermarket ECU's what kind or brand are you talking about? i may look into that if they are tune-able because i plan on installing a cam later down the road. not anything too heavy though.

[The Chainsaw]

No problem! The stock ecu DOES use the VSS for tuning in some spots, but very easy to work around it. I use the Holley HP EFI on my personal cars. Much easier to work with than the stock computer. Holley offers 3 ECU's that will work.

The "HP" is their basic ecu that has 4 inputs/outputs and will NOT control an Electronic transmission. ~$1500 with all the harnesses as a kit.

The "Terminator" has the same features as the "HP" but WILL control an electronic transmission. ~$2300 including the harnesses, but doesn't come as a kit together for some reason.

The "Dominator" has 20 inputs/outputs if I remember right, and WILL control an electronic transmission. ~$2600 including the harnesses, but also doesn't come as a kit.

There are a few other differences, but all 3 of those are very user-friendly while offering almost more tuning options than you will know what to do with.

[Project_70']

Well I'm back on here again needing some help, so far everything else is good, 5.3 and turbo350 are in fuel system is good, exhaust, ect.. But now I'm trying to wire the thing up, and I'm wanting to be able to start the truck basically like original, slip the key in, turn and start it. But I'm having trouble wiring the starter up, and tracing wires from the ignition switch and things like that. I've done some research but still having problems. So far this is what I've got, I have the battery in, from positive post straight to starter, then the little lead on the starter is wired to the purple wire going to the ignition switch. And I know I may be a little air headed at the time and just overlooking something simple but I can't get it to start. I just want to be able to turn the starter over with the ignition switch and find which wires to splice into for the pcm. I'm using the stand alone conversion from lt1swap.com. does the starter have to be grounded with the other post coming off the other side or is it case grounded?

[Project_70']

Originally Posted by Project_70'

Well I'm back on here again needing some help, so far everything else is good, 5.3 and turbo350 are in fuel system is good, exhaust, ect.. But now I'm trying to wire the thing up, and I'm wanting to be able to start the truck basically like original, slip the key in, turn and start it. But I'm having trouble wiring the starter up, and tracing wires from the ignition switch and things like that. I've done some research but still having problems. So far this is what I've got, I have the battery in, from positive post straight to starter, then the little lead on the starter is wired to the purple wire going to the ignition switch. And I know I may be a little air headed at the time and just overlooking something simple but I can't get it to start. I just want to be able to turn the starter over with the ignition switch and find which wires to splice into for the pcm. I'm using the stand alone conversion from lt1swap.com. does the starter have to be grounded with the other post charness ff the other side or is it case grounded?

Okay so after tinkering with with it for awhile I've got power to the starter when I turn the switch to crank it but all it does is just tick like I've got a lose ground or bad connection I just put brand new terminals on and tightened everything down good. Maybe the battery I'm using is too weak. I also would like yo hear how you guys integrated the old wiring harness into the standalone harness