Builds Brandi: 75 40 + 5.3 + fj60 H42 + splitcase .... build and lots of questions

[Augustiron]

Hi mud brain trust

I would like this to be in relatively open thread where people can post questions and advice from their own LS swaps into 40s, So it can be a goldmine same work.
I have spent countless hours searching and reading various build threads here and garnered a ton of information, thank you to all those who have contributed over the years.

Now that I am starting to place the engine in the chassis I realized there is a bunch of stuff I need to figure out that I haven't seen posted anywhere, So I will have a bunch of questions I hope the brain trust can help with.

I definitely bit off a mouthful for my winter project, I'm doing a lot of rust repair and body work in addition to the LS swap. I have already replaced the quarters, rear sill, rockers, some floor pieces, But I got sick of body work and decided to get started on the swap. I had the engine oil prepped and the transmission and transfer case already done, so I stuck them together this week and pulled the 2F (Which is for sale in the classifieds)

Background on the truck, had it for 5 years now and it has been an incremental build to make it a summer around town daily driver, the 2F runs okay but doesn't do well at speed at 6,500 ft where we live, I would really be able to do more with it with a V8 to go over some of the passes around here. I have two and a half inch lift, 33x10.5s, four-wheel disc brakes, 4x4 labs Saginaw steering, 4x4 labs rear bumper and full custom family roll cage.

I have a junkyard 5.3 of unknown provenance, I replaced the oil pump, timing chain, oil pan with an h3, bought a felpro full gasket set and replaced all the gaskets short of the head gasket, new crank seals front and rear, new metal "barbell", etc.
I understand small block Chevys and engines in general, but this is my first dive into an LS swap.

Some pictures to give you an idea where I'm at and then I'll start with some questions I need answers to

Thanks in advance

 

[Augustiron]

First question is about engine placement.

Front to back:
- I saw it mentioned that the front engine pulley gets lined up with the rear rivet on the shock tower.
I am currently using an FJ60 h42 long case + splitcase so I can get everything set up to switch to an h55 easily later on if I want the overdrive. I took measurements of my stock set up before I pulled it out and one of the measurements was from the firewall to the center of the shifter. With the front pulley maybe an inch behind the shock rivet, the shifter is an inch further forward. I feel if I slide the engine forward anymore the shifter will interfere with the heater.
With the engine in this position, my rear drive shaft is within a half inch of what it was with the 2F.
I am planning to use the stock mechanical fan which I do not have yet so I cannot check clearance to the radiator on the front.

How much wiggle room is there here and why did you set your engine forward or back? What were the driving criteria?

Left to right:
Front:
- The 2f was obviously set in at an angle and not centered in the frame rails.
Is the front of the LS centered in the frame rails? Does it matter?
If I center the pulley between the frame rails it looks like the AA adapter sits further over the driver side frame rail then the passengers. Which is odd.
I am running Camaro manifolds It seems like they will clear my saginaw steering shaft. (Edit: Nope 2010 Camaro manifold does not work on the driver side)

Rear: what is the driver for how to place the rear of the transfer case left to right?

Up/down:
Front: I've noticed people have blocks underneath the AA motor mount bracket to the frame when mocking up their engines. What thickness? Does it matter? Obviously getting clearance to the front axle and drive shaft Make me want to move the motor up and towards the driver side.

Tilt:
On the measurements I took before pulling it the two f was tilted down in the rear 3.7°, if I can I will mimic that with the LS.

So that's a lot of text, I guess the question is what are the drivers for engine placement and are there any couches or advice there?
Or is everything to set up specific you just got to figure it out and make everything fit for your own rig?

 

[Augustiron]

Pics of current placement sitting on 3/4" tubing

 

[Augustiron]

Dammit, looks like I'm not using Camaro manifolds.
The driver side comes down way over the frame rail. Passenger side looks usable though.
Guess I'll have to throw down some money for the Sanderson block headers that have been recommended 30x here.

 

[peesalot]

FWIW, I have a 2001 6.0 ls in a 1970 fj40, stock radiator & radiator location, my engine sits about 1.5" to 2" back further than your pic, I use the stock mech fan and theres plenty of room, you may be able to get away with that placement, I'll go see how much room mine has to move forward. I too used a camaro ex manifold on the driver side, had to sleeve the slave cyl hose with heat shield and built an alum heat shield for the slave itself as it's close. You see how the frame flares and drops on that driver side where manifold interferance is ? If you were to push motor back say 1.5" you can sweep that ex tube right into collector. My pass side ex comes around in front right in the step in oil pan, I wrapped ex from pass side to collector with heat wrap. Havent had problems yet & its been 16+ years. You may look at pushing motor to pass side 1/2" to help with that driver side ex manifold. Mock up the front half of split case and set motor so the pass side of tcase is off frame rail about 1/2", see if that moves motor to pass side a bit ?
What is a long bodied H42 ?

 

[peesalot]

Motor hiegth is gonna be as high as you can get before trans shift tower & tcase linkage start to hit tub bottom, you can tilt it a bit for dline angle but I hate that as it tends to drop bottom of tcase lower than I like. Set the tcase about 1/2" off pass rail and then look at how it hangs down, you wont get it flat across bottom but you can jack it up until tcase linkage will clear, then see if motor can come up. FWIW it looks to be at the right spot up & down, see if linkage and trans tower have room ?

 

[Augustiron]

Also worth watching, I have 3" of up travel between the axle housing and the front pulley, and then the third member and the oil pan

 

[Augustiron]

Thanks peesalot

Currently where the engine is sitting in the previous pictures, I pushed over the back of the transfer case so these shifter was more centered left to right and I have about 2 1/2" between the split case and the frame rail.

The height of the transfer case I currently have based on the height of the shifter Tower off the floorboard matching what it was with the old setup, which was 7 in.
Looking underneath the floorboard to the high low shifter it seems I have almost 2" more I could come up...

 

[Augustiron]

I jacked it up in the front to get 1 1/2" blocks between the frame and the AA motor mounts, this definitely helps with clearance between the pulley and front axle and doesn't seem to cause any problems.

Front to back I didn't move it, but there's only 3/4" between the back of the passenger cylinder head and the firewall, (driver side has a ton of room). That's definitely as tight as I would want to make that, so the engine is definitely not moving back. The crank pulley is also 3/4" behind the imaginary line between the shock tower rivets.

In the rear I jacked it up as high as it would go until something hit and it is the shaft the transfer case shifter pivots on contacts the floor, but I got it up about an inch from where it was. I tried the transmission tunnel cover It seemed to fit. I will have to modify the transfer case shifter a little bit but I knew that would be the case.

What's odd is in the front left to right spacing

If I measure from the frame rails to the center of the engine, it is currently a half inch towards the passenger side. But the AA mounts if you can make it out in the picture, they seem to be a half inch to the driver side.
Is the 40 frame not symmetrical in this area?

 

[peesalot]

I took another look at mine and your fan clearance should be fine, although close. That driver manifold is a center dump, I got an early 2000'2 ( 2005 IIRC ) camaro driver manifold and it comes out much diff than yours, its inside rail plenty and points down in front of slave, leaves just enough room to put hose on and have 3/4" clearance, hence the heat sleeve.
I would cheat that tcase up just a bit and over to pass side.

 

[Augustiron]

Do you have an SM 420 or GM trans? because my slave cylinder is on the passenger side with the H42....

 

[clrussell]

Good detailed info here.

Subscribing

 

[peesalot]

That diff clearance in front at what 4.25" now is proper, Wayes told me once that the up travel when installing ls in a 40 should be limited by the diff to pulley clearance so I believe you are spot on at that end, the clearance at pass corner of head is also very close to where mine is. Take a look at ebay and see if you can find a better fitting manifold, I hate headers, just my opinion. And FWIW I think my motor is at least that far to pass if not more. I just took a look and my tcase( orion with AA propeller mount ) is just about where your at, however the splitcase may be a tad larger so if anything maybe cheat it over just a bit more, but your close to home IMO.

 

[Augustiron]

I think I'm really close.

Here is a comparison of the measurements I took between the 2f before I pulled it and the LS as currently mocked up.

The only measurement that isn't almost dead on is the transfer case output is a little higher and more towards the center than what the old setup was. I can adjust the height by dropping the transfer case a bit but I definitely want to keep it as high as possible for ground clearance.

Another crazy thing is I currently have the front of the LS centered between the frame rails, but you can see in the measurements how far offset the front of the 2f was towards the driver side.

I remember the first time I did an engine swap on a 40 with a 2F and saw the engine sitting there without all the sheet metal and what a crazy angle it was at it freaked me out..

 

[Augustiron]

On the exhaust manifolds, I saw mentioned that Corvette C5 manifolds would work. That is interesting as they do dump between the middle two cylinders.

Edit: actually, looking at the photo of the driver's side manifold, the way the number one cylinder goes down at a 45° angle I think will run right into the AA motor mount. The passenger side definitely looks like it would work better but that is not where my hang up is currently.

Back to the drawing board

Also started looking at the transmission crossmember.
The benefit of using the FJ60 4 speed is that I can run a real transmission crossmember and mount under the transmission.
I have an 80 crossmember laying around here but the spacing for the two studs that come down out of the mount is a little different, easy fix, but I also don't know if it will be beefy enough as there is a lot more weight cantilevered on this setup it seems.

I may make something from scratch from box tubing and angle iron

 

[Mike Shull]

I used these manifolds to get around
my 3-link setup, but I had to modify the left side.

Summit Racing SUM-G9084B Summit Racing™ Cast Exhaust Manifolds | Summit Racing

Free Shipping - Summit Racing™ Cast Exhaust Manifolds with qualifying orders of $109. Shop Exhaust Manifolds at Summit Racing.

www.summitracing.com

Here are some pictures showing how I modified them: Builds - Stretched 1-Ton FJ40 - https://forum.ih8mud.com/threads/stretched-1-ton-fj40.1253008/post-14534387

 

[Augustiron]

Thanks, I recall reading your thread. Quite a beast.

 

[Augustiron]

Has anyone used these?

Flowtech PN 11706-7FLT

 

[ceylonfj40nut]

I used these manifolds to get around
my 3-link setup, but I had to modify the left side.

Summit Racing SUM-G9084B Summit Racing™ Cast Exhaust Manifolds | Summit Racing

Free Shipping - Summit Racing™ Cast Exhaust Manifolds with qualifying orders of $109. Shop Exhaust Manifolds at Summit Racing.

www.summitracing.com

Here are some pictures showing how I modified them: Builds - Stretched 1-Ton FJ40 - https://forum.ih8mud.com/threads/stretched-1-ton-fj40.1253008/post-14534387

^^^ this!

 

[Mike Shull]

Has anyone used these?

Flowtech PN 11706-7FLT

View attachment 3854017

I haven’t run these on my LS but I did have a set of chrome headers on my 2F and then on my SBC in my same LC. My experience was that both headers heated up the engine compartment more than my cast iron manifolds and it made the inside of the Cruiser very hot to drive long distances on the highway (8-10+ hour drives). I ended up switching my SBC headers for center dump Corvette cast iron manifolds, which were quite a bit cooler. This is the reason why I went with cast iron manifolds on the LS, especially since the LS typically runs hotter than a SBC or the 2F.

You may have noticed in my thread where I mentioned that I probably wouldn’t run the same manifolds again, and that was because I wasn’t confident that the exhaust would fit well. The exhaust fit perfectly fine in that tight space and I imagine that I’ll run it this way for a long time. I have driven it 600 miles so far with this setup and it works great.

Below is a link to pictures showing how tight the exhaust is. Pictures 2 and 3 are showing the left side by the manifold.

Post in thread 'Stretched 1-Ton FJ40'
Builds - Stretched 1-Ton FJ40 - https://forum.ih8mud.com/threads/stretched-1-ton-fj40.1253008/post-15655431