Old and New: 5.7 Vortec to 6.0 LS Swap, ‘69 FJ40 (3 Viewers)

[Rock40]

Finally making some time for this in between working on the ongoing M715 build

Here’s the FJ40…

I’ve owned this since 2000 when it was a bone stock rusty basket case. It’s been through the standard evolution of changes.

In 2003, I installed the Vortec 5.7 from a 1996 Suburban and at that time, I think that swap had only been done a handful of times in an FJ40. Fast forward 21 years and the truck has driven all over the western US, back and forth to Alaska on the Alcan and has tackled some decent trails. The engine has always been SOLID but I’m looking for more horsepower than the maybe 250HP it’s cranking out

Bought a 2001 6.0 LQ4 in 2017 (yeah none of my projects happen fast ) now it’s time to install it

Engine was fully rebuilt although it only had 40k on it. Looked like the previous owner treated oil changes as highly optional and the motor was full of sludge. Did a mild Texas Speed camshaft and after a LOT of research, installed 862 heads from a 4.8 LS engine. Had the heads milled .035” also.

The 862 heads are already higher compression than the standard 317 heads on these engines. It “should” be about 11.5:1 compression and will need to run on 93 octane. Looking at dyno results from others, the engine should make all its torque and HP under 5,000rpm which should be ideal for wheeling. Guesstimates say the 6.0 should be right in the neighborhood of 430HP

Tore the truck down today…

 

[Mike Shull]

Sweet!

 

[Mike Shull]

What is the setup of the rest of the drive terrain? Is that an FJ80 master cylinder?

 

[EWheeler]

What is the setup of the rest of the drive terrain? Is that an FJ80 master cylinder?

@Rock40 and is that routing for an in-cab adjustable proportioning valve, or for an in-line line lock, or both? Bitchin 40.

Also what is your long term feed back on the durability of the AA Rockbox? I've got two of them, one in a 40 and one as a spare. Have you had it in place for all those miles over all those years?

 

[Rock40]

What is the setup of the rest of the drive terrain? Is that an FJ80 master cylinder?

Yeah, that’s an 80 series master in front of a 2nd Gen mini truck booster

Rest of the drive train is a 1952 SM420, AA Rockbox and AA Orion. Rear axle is currently a FF 80 series (Teraflex CRD 6O is in the works) and the front is a narrowed ProRock 60

 

[Rock40]

@Rock40 and is that routing for an in-cab adjustable proportioning valve, or for an in-line line lock, or both? Bitchin 40.

Also what is your long term feed back on the durability of the AA Rockbox? I've got two of them, one in a 40 and one as a spare. Have you had it in place for all those miles over all those years?

Thx, yeah, it’s actually both. The proportioning valve and line lock are right under the steering wheel essentially

And yes, the AA Rockbox was installed in 2003 also, I’ve done ALL my hard wheeling with it and all the road miles. About 35,000 miles total. I haven’t had a single issue with it, I don’t think it’s ever even popped out of gear. Good thing since they are NLA. Wish I had a spare

 

[EWheeler]

1952 SM420, AA Rockbox and AA Orion.

Damn! 4:1 Orion? If so, your lowest crawl ratio possibility is over 400:1 !?!

 

[Rock40]

Damn! 4:1 Orion? If so, your lowest crawl ratio possibility is over 400:1 !?!

Hahaha! It’s actually 352:1 I run 3.7 axle gears because I have PLENTY of trail ratios to choose from and I still drive on the highway a lot. Drove to the Rubicon towing an M416 from northern WA most recently.

I rarely use the AA Rockbox unless I’m in some really nasty stuff, usually I just run low range and row the transmission gears

 

[74fj40]

I’ve always like your 40, lots of cool details

 

[Rock40]

I’ve always like your 40, lots of cool details

Thanks VERY much, it’s been a labor for sure, they all are. Definitely time for a little refit

 

[boots4]

Great seeing more projects from you. Rig is pretty clean for all those years. It's always nice when things come apart as intended.

 

[Rock40]

Agreed. Missed you at the last CTW last year. Goal is to get this done before a Rubicon trip with @CreeperSleeper and a few others this August.

 

[boots4]

Yeah, since we moved out to Sandy 2 years ago I haven't seen much of the group or been involved. Been doing house stuff so my rig mostly just sits around at the moment but I love having a shop with a lift now to work on stuff. I've been out to LaDee Flats a couple times but there's only three main trails for rigs, but at least it's close. Rubicon has always been a good time. I'm debating a Moab run this year since we'll be visiting family out that way and I could slip away for a couple days to go play.

 

[Rock40]

Yeah, since we moved out to Sandy 2 years ago I haven't seen much of the group or been involved. Been doing house stuff so my rig mostly just sits around at the moment but I love having a shop with a lift now to work on stuff. I've been out to LaDee Flats a couple times but there's only three main trails for rigs, but at least it's close. Rubicon has always been a good time. I'm debating a Moab run this year since we'll be visiting family out that way and I could slip away for a couple days to go play.

Cool, that makes sense. I’m currently building a shop too, just not enough time for everything

Moab is damn awesome but man it has gotten SO damn crowded in recent years. Heard they recently shut a lot of good trails down too unfortunately.

I’m sure we’ll run into each other again in the future

 

[Rock40]

Well…. The 5.7 Vortec is now out. Pulled the headers and exhaust crossover and it JUST fit getting it out past the shock hoops and shock crossover bar

Mocked up the 6.0 to check clearances. Still waiting on the McLeod clutch so there was no bolting it up today anyway.

Surprisingly it was easier to get the 6.0 in/out than the 5.7 liter.

All the plastics fit, shock crossover fits, exhaust crossover fits, intake should fit, steering shaft “might” fit. AA adapter engine mounts look like they properly convert the LS so it’ll bolt up to the frame mounts for the 5.7, all and all, not bad

Unfortunately the firewall does NOT fit as the LS heads are much taller. It’s drawn out here but essentially the engine needs to move backwards 1.625” to properly mate with the transmission. Stinks because the interior is Line-X’d and the transmission tunnel will need to be modified also. Could be worse tho

 

[Rock40]

Lots of little stuff

Did the measurements to determine what clutch pilot to run. This is a different SM420 and bellhousing but it was easier than working in the truck. Input shaft stick-out from the bellhousing face measured .290” so the internet said I could use the large GM roller bearing, P/N 12557583

Cut the passenger side firewall and transmission tunnel. Bottom line is that the 6.0 LS is just quite a bit larger than the older 5.7

Passenger side header just clears the shock hoop

And here’s the passenger side head protruding through the firewall

 

[Rock40]

Clutch stuff

Upgraded to an SFI approved McLeod flywheel. Billet steel, 30 pounds and correctly offset to run the old SM420 and bellhousing, P/N 460535

Flywheel is held onto the crank with ARP bolts, GM specs said 74 ft/lbs, ARP said 85 ft/lbs. Torqued it to 85 and called it a day.

My cousin hooked me up with a chunk of old flex plate. Wedge it in against the flywheel, run a bolt into the block and it prevents the engine from turning as you torque the flywheel bolts.

Shot of the SM420 input shaft and the clutch pilot. This is with the engine in place. Good example of correct input shaft to pilot bearing clearance

 

[Rock40]

Stripped the firewall down, removed the ARB compressor, Painless dual battery manager, battery, buss bar and a few relays

Welded in some nutserts for easy installation of parts. Ditched the buss bar and circuit breakers, going with a Blue Sea 6 circuit box to power the accessories

 

[Mike Shull]

Hahaha! It’s actually 352:1 I run 3.7 axle gears because I have PLENTY of trail ratios to choose from and I still drive on the highway a lot. Drove to the Rubicon towing an M416 from northern WA most recently.

I rarely use the AA Rockbox unless I’m in some really nasty stuff, usually I just run low range and row the transmission gears

And I thought that my setup was crazy at 187:1 .

 

[Rock40]

And I thought that my setup was crazy at 187:1 .

Lol, yeah 187:1 is plenty, that is a good ratio.