Another ls swap from a new guy

[SlowGreen71]

Hey all. Been lurking a long time and just joined. Getting started on a 6.0/4l60e swap. Going into a 71 K20. Truck currently has a mid 70's 454, TH350 and a 205. So far I've put in a new wire harness from AAW replaced the carb and intake with edelbrocks and undone a lot of handy work from previous owners. I bought a complete 2001 Yukon Denali for a donor vehicle for $1,000. So far plans include keeping the stock radiator and welding in a bung for the steam line and using windstar fans. Motor mounts are sliders I bought on Amazon and have some plans drawn up to build a clean, simple bolt in crossmember. Transmission to transfer case will be a 205 using a 6 to four bolt adapter followed by a spacer to take up the length of the trans output shaft. Both from advance adapters. That'll leave about a 1/2 inch to trim off the shaft and it will be completely bolt together rather than changing the shaft while leaving the t-case in the stock position and moving the motor forward shy of a couple inches. For the fuel system I'll use the stock tank and pump regulator combo from speedway. I'll do my best to keep this updated. Anyway, questions, comments or suggestions are always welcome. I'm still figuring out how to correctly do the picture thing but, here is the recipient, donor and some of today's greasy work. So far the worst part was getting the DBW wire harness separate from rest of the harness

[ls1nova71]

Just an FYI, but you can get the jumper harnes between the TAC and pedal from an '03-05 truck so you dont have to try and dig it out of the '01 harness, but it sounds like you've already done it.

[SlowGreen71]

That'd be good to know for the next go round, thank you. I did however get it out cleanly.

[mongocanfly]

welcome...nice build....you could also switch to dbc throttle...that's what I did on mine. ..

[BR3W CITY]

That donor truck actually looks like it was in decent shape, is something terminally wrong with it?

[SlowGreen71]

A little more progress today. Engine and trans out. I just pulled them together and left the t case hanging in place still attached to the driveline and a 4x4 to prop it on the crossmember. I did this alone today and it wasn't too bad although hindsight I'd pull the motor separately. Required a big turn in the engine bay and a lot of height for the picker. Bent my trans dipstick in the process. Here's a couple pics. Below also is the two adapters I got to better explain how I'll be mating this to a 205. I realize it does add some length to what will be the weaker spot of the set up, but this is solely a cruiser so it's not much concern. Thoughts?

[SlowGreen71]

Originally Posted by BR3W CITY

That donor truck actually looks like it was in decent shape, is something terminally wrong with it?

Nothing really wrong with. It was a nice rig in it's day. Completely loaded with a 6 inch lift. Inside smells like, well.. laziness I guess would be a good way to put it. It was wheeled pretty hard for awhile. The front end is shot. My test drive lasted 2 mins and 25 mph. Couldn't control it over bumps etc. otherwise just neglect and lack of maintenance. It did have a couple codes when I bought it. One was a miss which just turned out to be a very loose plug. Threads are still good. The other had something to do with a vacuum problem in the fuel system. I did find a vac line had come apart when I pulled the intake. Hopefully that was it.

[thehata1]

Awesome truck!

[izzy_Britton]

Originally Posted by SlowGreen71

So far plans include keeping the stock radiator and welding in a bung for the steam line and using windstar fans.

There is also an option to tap the water pump and plumb the steam line to the pump.

There is a nice build where the builder does the steam line to the water pump thing.

HERE

I plan to duplicate this as well. I understand that the steam lines are supposed to be the upper most portion of the engine to allow for steam/vapor to vent the engine and exit out the fill hole in the sealed 99+ radiator overflow bottles, but i believe that if the steam line is plumbed to the water pump, the steam/air/vapor will eventually be cycle out of the upper most portion of the engine and exit via the radiator in the same manor as originally designed, only differently.

If you were closer, i would be totally interested in the carcass of your donor truck.

[SlowGreen71]

Originally Posted by izzy_Britton

There is also an option to tap the water pump and plumb the steam line to the pump.

There is a nice build where the builder does the steam line to the water pump thing.

HERE

I plan to duplicate this as well. I understand that the steam lines are supposed to be the upper most portion of the engine to allow for steam/vapor to vent the engine and exit out the fill hole in the sealed 99+ radiator overflow bottles, but i believe that if the steam line is plumbed to the water pump, the steam/air/vapor will eventually be cycle out of the upper most portion of the engine and exit via the radiator in the same manor as originally designed, only differently.

If you were closer, i would be totally interested in the carcass of your donor truck.

Thanks Izzy, I'll look more into this. I'd prefer find the cleanest way to do it. I'd like everything to appear as stock as possible.

[Devil Pup]

Nice looking truck. I really dig the green. How many miles are on the motor/trans set up? I ran the windstar fans on my swap and they keep my truck nice and cool, good choice. You're gonna love the LS.

[SlowGreen71]

Originally Posted by Devil Pup

Nice looking truck. I really dig the green. How many miles are on the motor/trans set up? I ran the windstar fans on my swap and they keep my truck nice and cool, good choice. You're gonna love the LS.

About 180k. More than I'd like it to have but it runs well and for the price it seems to be worth it. You have any pics of how you mounted the windstar fans?

[Devil Pup]

Originally Posted by SlowGreen71

About 180k. More than I'd like it to have but it runs well and for the price it seems to be worth it. You have any pics of how you mounted the windstar fans?

I do. post #94 on my build thread. it might be different than yours though because i have an aftermarket radiator.

[suburban99]

Finished my LQ4 swap last year on my '72. I used the existing TH350 as is was recently rebuilt. Going to swap in a 700r4 soon. I used the dirty dingo cross member and sliders. I tapped my water pump for the steam outlet and also tapped the water pump for the stock sending unit for temperature gauge..truck is a blast to drive.

A few things other things I did with the LQ4. New front and rear main seals, new intake gaskets, new valve cover gaskets included the bolt hole grommets, pan gasket, front cover gasket.

[SlowGreen71]

Not a whole lot of progress to report this week as it's been a busy one. Got the engine and trans cleaned a little and separated. A little fitnent of the headers, motor mounts and a/c bracket. Looks like it'll work. Should be pulling the engine and trans out of the 71 on my next days off. Oh, and my cat is sleeping on the job apparently. I guess old chevys make great mouse houses.

[SlowGreen71]

It's been awhile since I've been able to get some work done on the swap. Work and life have been getting in the way. I was able to get the truck stripped down and cleaned up. The previous owner did some quality work getting the big block and manifolds to fit. Come to find out none of the motor mount bolts were tight and half the cross member bolts were barely snug. Here's a few picks of that.

On another note, I sold off the remaining carcass of the Yukon and traded the stock big block for a running and driving 2001 suburban with 5.3/4l60. The suburban was soft rolled but still great for some our purposes. The remains of this is already sold off taking my investment for both engines and trans to zero.

[SlowGreen71]

I did a little horse trading and picked up a rebuilt np205. It's been sitting in a shed for a number of years. Needs cleaned up and painted but will be a good replacement for my leaky and very noisy stock case. I did a little dry fitment of the trans and t case along with the spacers from advance. I needed to cut off 3/8" of the tailshaft and it all slid together nicely. Once I got the trans assembly bolts back in to place I dropped in the mock up block I got from a friend of a friend. Sure makes things easier to position and check fitment. I used the stock holes for the rear crossmember and with the spacers it placed the back of the engine about 6 inches from the fire wall. Pan clears the front 3rd member. So far this placement looks like I will be able to use the stock a/c bracket and compressor. Although the fittings will be very tight I think it's doable. Headers from speed engineering are tight to the starter and I may need to trim an ear from the bell housing. All in all it sits nicely. Within a couple degrees of angle as it was in the yukon. Sorry for the crappy pics, but you get the idea. I'll have a couple hours today to start working on motor mounts.

[SlowGreen71]

A couple more showing how it landed and clearances.

[BR3W CITY]

moving along dude

[SlowGreen71]

In between kids and work I attempted to get the engine and accessories cleaned up a little. Lots of super clean and pressure washing. Got a little time to get some motor mounts done. Looks like everything will clear easily. A little finish welding and some paint and they will be finished. I'm not a fabricator by any means and I've definitely built prettier things but these should work. I bent up some 3/16 plate into a c channel for frame insterts bolted into the original mount locations on the frame and left them long to make future combinations of motor placements easier. The rest is cut out of 1/4 plate and bolts together. It's a little hard to see but the crossmember is removable to access the oil pan if need be.

[SlowGreen71]

Aluminum template I cut out for the mounts. Made layout much easier. For a fuel return I'm using a new fuel sender. I drilled a hole and bent up some fuel line from napa. All they had was this coated stuff. Hopefully the poly coating doesn't affect soldering it in place too bad. Also got my radiator flushed and brazing in an 1/8 npt bung for my steam line.

[El_C10]

Awesome work!! following this thread for sure.

[SlowGreen71]

Little more work done today. Got my fuel system mostly laid out. Still have to bend the hard lines from the sender to the flex lines at the pump. I redid my motor mounts. They didn't turn out as well as I'd hoped the first time. Anyway, here's some pics. If anyone sees anything that could work better, please share!

[izzy_Britton]

I really like the way you did your fuel sending unit setup. Looks pretty slick!

Keep it up.

[1970 CST Short Wide]

Originally Posted by SlowGreen71

Thanks Izzy, I'll look more into this. I'd prefer find the cleanest way to do it. I'd like everything to appear as stock as possible.

I had the Rad shop put a nipple in my top tank to run steam line to. I have my original rad and it works fine.

Looks like you got a nice build going. Welcome to the site and bears of luck with your build. You’ll always fine some kinda help here

Steve
1970 CST