'71 k5 "Cowboy Cadillac" LM7 swap... Over the hill

[79bonanza]

dang another piece of ply wood. i found a big rock to work on but hade to move back to the dirt. just couldnt handle such a high quality work area. lol

 

[76zimmer]

I want to pry that tab out away from the center axis of the post right?

Right, its just spring metal, and there is a tool made just for that, but if your careful, you can just use a pic tool to pull it away from the post, then try to evenly pull up on the arm.
Like I said that is sometimes a little difficult because of the spring between the the base of the arm, and where the arm extends out to the blade.

Here you can see the tab...

 

[TruckinFool]

Awesome man, thanks. Just wanted to make sure before I go breaking something hah.

Due to 3 exhaust bolts, missing sawzall, 1 trans cross member bolt, 4 driveshaft nuts, POS autozone engine leveler and a busted knuckle nothing came out today.

NOT ONE problem due to the truck being 40 years old.. All the jackass before me. I HATE this part of builds.

 

[buefchris]

Due to the fact that it's over 40 years old,makes it hard to tell just how many Jackass's where to blame.
Stick with it, it will be so nice in the long run

 

[TruckinFool]

I hear ya. I guess your always in for one or the other. If there's no rust.. its gata be "jigga" rigged.

On the plus side the drive train did come out today. Inspected and started cleaning up the 205, Painted the DIY4x mounts and did some reorganizing so the bears don't call the HOA. hah

See what I can manage tomorrow

 

[shovelbill80]

very cool thread....i'm learning a lot from everyone here, thanks. you DO get to work at night with drop lights AND a campfire................cheers, Bill

 

[TruckinFool]

Messed around with the DIY4x mounts. Although these are not designed for use with LS style motors I REALLY like these over the alternative mounting option (cost/design/quality and the other requires a min 4" lift) and I wanted something that will work at stock height.

These newer style DIY4x mounts use a removable cross bar that doesn't clear the LS pan.(Pic on his websites outdated) I figured these would be perfect in hopes that all I would need to do is redesign the bar. Ordered without the bar and crossed my fingers.

Here's some pics:

Measurements from the tip of the bump stop to its contact pad is 2 3/8" (stock height without engine) Edge of the cross bar mount straight down to where it would hit the pumpkin is 4 1/4" (stock height without engine) Take off about 1/2"-3/4" if the axle comes up at an angle.

The bump stop would need to compress a tad over 2" before anything makes contact. I have no idea how much the stock springs flex or bump stops compress but I know my stock front end is really stiff. I'm thinking this clearance would be ok for everything but maybe aggressive offroading. It got dark so I'll look into it more tomorrow but if need be I can chop the mounting plate off and re-weld it closer the the poly mount.

 

[thealien]

I tried using his crossmember and one he reworked for me. I ended up using his frame mounts, motor mounts, urethane bushings and sleeves and welded my own up with chrome moly tube. Here are a few pictures...

Here are a couple of pictures of what I ended up with. I used 1 1/2 inch tube .250 wall.

Even with the smaller 1 1/2 tube compared to his 1 3/4 tube and making the crossmember so it hugged the engine/oil pan closely I still had to notch the crossmember to clear the front differential. With the .250 thick walled tubing and we made the notch almost solid.

I have lots of pictures in my photobucket acount, feel free to check them out and ask any questions you might have. I have almost 3000 miles on my swap now and am very happy. Runs strong, no leaks and everything works as it should.

http://s49.photobucket.com/home/screagle2000/index

 

[TruckinFool]

Judging from where your notch is I'm thinking the flange is ok where it is? Thinking about it more, even if the axle comes up at an angle it shouldn't hit. My rough thoughts for the cross bar is to go with a thick L or C channel shape to avoid the pumpkin. What do ya think?

What are the options for the oil pressure sending unit? I noticed yours in your photo album. Is there enough room to ditch the hose between the adapter and sender? Do you remember the factory sensor thread type/size?

 

[thealien]

Judging from where your notch is I'm thinking the flange is ok where it is?

What flange are you talking about? The one that the bottom half of the crossmember bolts to (the part that allows the crossmember and oil pan to be removed)? If that is what you are talking about NO, the angle of that part and flange aims the crossmember at the engine. If you are talking about the frame flange than yes. I expected to have issues so I had Kurt at DIY 4X4 send me an extra set of bushings, the tube they fit into, and an extra set of plates that bolt to the frame c channel.

Thinking about it more, even if the axle comes up at an angle it shouldn't hit. My rough thoughts for the cross bar is to go with a thick L or C channel shape to avoid the pumpkin. What do ya think?

If I was to do it again I would just use the motor mount bushing part and completely remove the crossmember until the engine was installed (these engines are designed as a stressed member and the newer trucks don't even have a crossmember but their frames were designed with this in mind). After installing the engine I would then make the new crossmember angled away from the pumpkin however I kind of like that my front differential would hit the crossmember instead of the oil pan. I am still considering a 2 inch lift for additional clearance but I have not hit. I also don't offroad it but the roads around here are kind of like off road?

What are the options for the oil pressure sending unit? I noticed yours in your photo album. Is there enough room to ditch the hose between the adapter and sender? Do you remember the factory sensor thread type/size?

What hose are you talking about? I believe the factory threads are 16 X 1.5 metric and our original hard lines fittings are 1/8 NPT. There are adapters out there for this and you can ditch the factory sender as the PCM does not need it. I wanted both (why I had a T fitting made) because I am also going to be running an aeroforce guage that can read it through the PCM.

Over the winter I hope to put together an informative all in one place build thread. For now I have just been having fun driving it!!

Here are some links to lots of information I have gathered..

http://67-72chevytrucks.com/vboard/showthread.php?t=380683

http://67-72chevytrucks.com/vboard/showthread.php?t=378317

http://67-72chevytrucks.com/vboard/showthread.php?t=388263

http://67-72chevytrucks.com/vboard/showthread.php?t=389895

http://67-72chevytrucks.com/vboard/showthread.php?t=386784

http://67-72chevytrucks.com/vboard/showthread.php?t=376833

http://67-72chevytrucks.com/vboard/showthread.php?t=382547

http://67-72chevytrucks.com/vboard/showthread.php?t=375380

 

[TruckinFool]

Oh ok, Didn't realize the computer doesn't use it. I'm just going to run an autometer for it.

Primed:

I went through an epic personal battle at the parts store trying to decide if I should go with a black or khaki firewall. The parts guy actually came up to me and asked if I was ok haha.

Khaki Paint:

Mounts:

 

[63chevyll]

looking good,

i always hate cleaning and painting firewalls.

Always turns into a "where do i stop" project

But yous is coming together well

 

[buefchris]

I second that! I guess it depends on how much you want to show off , or do you just want to use it and make it simple and reliable.

 

[TruckinFool]

Thanks man, Tight budgets help with constraint haha.


Ok, So wtf am I doing wrong here? I never remember reading about anyone having to smash in their firewall doing this swap?

Driveline is like this 5.3l-th350-np205

I have it bolted into the factory frame holes and trans crossmember but this is causing the heads to hit the firewall. What gives? Is this normal or did my dumb ass put the trans crossmember in backwards? (if thats possible? looks the same both ways to me?)

Another thing is my LSX-SBC motor mount adapter plates are supposed to allow stock, 1" forward and 1" back mounting locations. Right now its landing in the 1" back location.

 

[texas4x4rebel]

It looks like in the photo of your motor mount adaptor you have it bolted to the one inch back positon. Try the stock or one inch forward.

 

[TruckinFool]

Thats the thing though they need to be in the 1" back to meet with the crossmember position which is in the stock holes.

 

[thealien]

Since I used a 4L60 with my NP205 in the stock location my engine is about 2 inches forward which worked perfect for me (except for the differential clearance). I had to kind of custom drill/make my adapter plates to accomodate this. I went this route because I didn't want to have to cut my floor for the shifter or replace my fairly new driveshafts. Everyone is doing these swaps on 2WD, we are kind of the pioneers doing them in 4WD. It was a big expense to mate the 4L60 to the NP205 for added fuel mileage. You are the first I have read doind the swap in a 4WD with a th350. Sorry I don't know what to tell you here. You might want to give Kevin at Pacific Fabrication a call. He is pretty knowleageable with LS swaps in 4WD.

 

[deadman]

Have you tried switching the crossmember the other way around to see if there is a difference? Might want to give it a try. You might need to move the crossmember forward in order to clear the firewall. I've never done one of these swaps, so i can't speak from experience, so i'm just taking guesses here.

 

[texas4x4rebel]

Option 1 big hammer
option 2 new drill bit

mine fit fine at the fire wall with the th350 and the 1in back but mine is also a third gen.

 

[thealien]

Have you tried switching the crossmember the other way around to see if there is a difference? Might want to give it a try. You might need to move the crossmember forward in order to clear the firewall. I've never done one of these swaps, so i can't speak from experience, so i'm just taking guesses here.

The crossmembers are the same either way, mine was anyway. There might be a slight difference depending on how it was riveted together. I guess it wouldn't hurt to try but I don't think it will help.