Thinking outloud... engine swap in the 40

[Rezarf]

I have been thinking a lot lately about a possible engine swap in the 40.

I have been really diggin' the LS1 series of engines (especially the cast iron counterparts in late model GM trucks) and think it would a fantastic power plant in the 40.

I really want:

• Mo' power to pull up the passes at more than 35mph.
• To tow the trailer with ease
• I want fuel injection
• I want the gas mileage gain I think I could get from this motor
• I want a new project to keep me busy in the garage
• I want a hot rod, but I have a 40

I realize the list to do this swap is long, but I am impressed with the aftermarket support for the LS(x) engines that is out there. I realize the 40 would be down for the count for a while, but that is accpetable.

What I am wanting to hear from you guys/gals is:

• What tranny to run?
• What transfer case to run?
• What are minimum upgrades to the rest of the "system" axle shafts, fuel requirements, radiator, etc...
• A good source for a complete pulled motor here in Denver?

I am thinking I'd like a LS1 (or cast iron equivalant) and a nv4500 with the 40 factory t-case (beefed up)... , but I am wondering what parts will start to blow up quick with that kind of horse power and torque?

I have also considered the idea of a 4.7 toyota engine in there but the power in my Sequoia has never blown me away. I think the aftermarket for the chevy motors is incredible from wiring harnesses to shear info on the www.

I am just thinking out loud, but this is certainly on my next "big project" list.

 

[LXBRADY]

I have a V8 in my 40 and I like it. I love the sound, it pulls up I-70 ect, but it is built for the trail so there are trade offs.

My V8 is a fuel injected out of a 92 buick roadmaster(350). Factory spec. 180 hp 300 ft/lbs. I have dual exhaust and no cats so maybe 225 hp.

I have a GM SM420 with a granny first, great for the trail, but only a 3-speed on the road. I see 11-12 MPG.

My stock t-case gave up the ghost after 40 years of service and dropped in an orion 4:1, agian for the trail not the street. That said it will do 70 MPH easily all day.

I have not torn up anything yet, mostly because the motor is fairly mild.

Once you move away from the 2F you will need to support the t-case in the rear, I suggest you talk with Justin from Redline for a t-case mount.

I would say go for it, because it will breath new life into your 40 for the reasons you stated above. If you are fairly mechanical, listen to those who have been before you and go easy on the HP you will be fine.

Just need to decide to built it for the street or the more hardcore trails.

Good luck and have fun with it!

 

[Rezarf]

Thanks Steve! Yeah, my Cruiser has been my DD for 12 years now. I would like to split the middle on street/trail. It is my DD, but it won't be our long road trip vehicle for the family so building it with the trail in mind has always been part of the equation.

 

[subzali]

Drew, have you ever driven a V8 powered 40? Even without many engine mods they are dang fast. I would stay away from the 4.7L unless cost is no factor and you have the time to figure out the wiring harness issues, not to mention fitting that engine with probably an auto (though I think there are some 5 speed 4.7L running around that people have swapped, not sure what tranny though) and trying to squeeze that into the wheelbase of the 40.

I wish I could call dibs on your engine. I would like to have a late model 2F sitting around for future possible mods...

 

[Rezarf]

You can call dibs, this is most likely a half a year to a year out.

And yes, fast is welcome

FWIW, some of the cast iron models are being sold for $750ish complete with all the accessories with around 75-80k miles on them. Thats cheap. Also, if I pony up the coin, folks are out there making custom wiring harnesses for this motor and its not much more than a painless kit for a fj40.

 

[Air Randy]

I have the LS1 setup in the Meanie, love the instant starting with the FI, always runs smooth, etc.

Several ways you can go. You can get an adapter (Mark's Offroad) that will allow you to run your stock tranny, tcase, etc. The adapter is expensive ($1200) but it allows you to keep your stock drivetrain exactly the way it is today. It gives you a bell housing the toyota tranny and rear 2F motor mounts attach to, and an input shaft extension that slips over the stock toyota one. You then use a specific chevy clutch/pressure plate and your stock clutch fork and slave cylinder. No changing of driveshafts, crossmembers, nothing. You even use the rear 2F motor mounts to ensure everything is properly aligned. The stock tranny/tcase should be strong enough behind the LS1 as long as you aren't really abusing it.

In the Meanie we have a TH400 automatic. If you want to go automatic go with a TH400. They are dirt cheap to buy and rebuild and they were made to go behind high HP v8's. Of course then you are going to be making big mods to the rest of the drivetrain since you will also need a AA or Orion Tcase, new driveshafts, new rear crossmember, console shifter, etc.

I've thought about dropping a V8 into the Blue Mule and have concluded, if I do it, I will go with the adapter and keep everything else as-is. Of course I already have an H41/orion setup too.

 

[Rezarf]

Great info, thanks Randy.

 

[74fj40]

Drew an LS1 would be an excellent power plant. I do agree with randy about the th400 for the most part, strong and easily sourceable transmission.

BUT don't rule out a 700r4/4L60e. Since you are also doing this swap for gas mileage reasons, the 700r4's and 4l60e's are 3 speeds with overdrive and the th400 is only a 3speed. That overdrive would significantly lower your RPMS on the highway giving you better MPG.

But if you want a manual, there are several options, easiest would be an adapter to use the stock trans and xfer completely. If you want to get technical, you could use an nv4500 which would be a 5 speed manual!


As for the transfer case, go with an adapter to stock or to orion. If you choose an atlas or something it starts to get difficult due to differential postions.

There are plenty of options for chevy powerplants, practically everything bolts to it.

Good luck!

 

[RLMS]

TBI motors are a great cheap way to get a v8. As randy states the marks adapter is a good choice, we just put this exact setup in a 60! However TBI's like to run in the 210* range. With that said an aftermarket rad. and Dual spall fans with the spal controll computer is the ONLY way to keep these 100% cool, no matter the conditions. Throw on a set of Ram horn manifolds as well, you will pat yourself on the back. no steering clearence issues, ect..


Justin

 

[LXBRADY]

However TBI's like to run in the 210* range.

Tru that!

 

[PhatFJ]

Here is my , did my 5.7L swap last year, took it out of a 1993 Suburban. BIG plus, got to here it run before I bought it! Got the motor, complete harness STOCK and all necessary sensors, relays and computer for under $400.00. Wanted to go with TBI for reliability and performance. I am running an SM-465 4spd w/ granny low. I went on e-bay and bought FSM manuals including ALL electrical and emissions, these were invaluable using the stock harness. Not being OBD2 the diagnostics are quite basic, pulling codes off the SES light. I ended up going with a new PCM which I could program http://www.dynamicefi.com/rather than going with a custom chip burn (one time only). Now if I change anything I can re-program myself. I am still learning but really like the system and the support. If you go this rout you will need to install a VSS so you can send necessary information to the program. This is a great project and I am really enjoying it.. If you do get into this and have questions please feel free to contact me, I will be happy to help where I can.. Good Luck!!

 

[Rezarf]

I have been reading for weeks. A 5.3 is in my future. A short discussion with Marco put me over the top. I am going to gather parts this winter, read till my eyes hurt, force Marco to want to help me and dive in early spring and hope to have a Gen 3 GM motor before CM12.

Tube work (cage, fenders, sliders) this fall/winter, engine in the spring/summer, body and paint next winter. Hopefully, I can do it with only a month's downtime.

I may add wheelie bars and a parachute but the jury is still out. On a serious note, I gotta' look at a brake and cooling system upgrade.

 

[subzali]

If you get a 60 series top plate for your transmission, I think you can do the swap without having to move your shifter into your heater. Maybe. You're going total darkside on us dude.

 

[rover67]

Sweet!

Let me know when you need anything!!

 

[Air Randy]

If you get a 60 series top plate for your transmission, I think you can do the swap without having to move your shifter into your heater. Maybe. You're going total darkside on us dude.

If he goes with the Mark's Offroad conversion kit, the 5.3 will drop right in to the 2F motor mount locations and the rest of the drive train will remain in the stock location, so no worry about shifters moving, changing driveshaft length or driveline angles, etc.

 

[subzali]

If he goes with the Mark's Offroad conversion kit, the 5.3 will drop right in to the 2F motor mount locations and the rest of the drive train will remain in the stock location, so no worry about shifters moving, changing driveshaft length or driveline angles, etc.

Well there you go Drew

 

[rover67]

hey Randy, do you have a Mark's kit in Meanie?

 

[Air Randy]

No, because it has the TH400 tranny and AA TC.

But I was thinking about converting the Mule to a 5.3 but wanted to keep the stock Toyota 4 spd/drivetrain, etc. I researched it and the Mark's Offroad kit uses an input shaft extension, a chevy clutch and a bellhousing adapter so the rear motor mounts on the 5.3 use the rear 2F mounts and the adapter positions the drive train so everything stays in the stock location. That way you dont have to deal with fabbed up cross members, etc.

 

[Rezarf]

Well there you go Drew

See post #6

 

[rover67]

I had to fix a few problems with the clutch with my Marks kit. The shaft extension wasn't quite right and didn't engage the pilot bearing correctly. I asked because if you had one in meanie I would have been interested in talking to whoever set it up. But yes, now I remember you have an auto in it. If you choose that route I can share with you my struggles. My preference would be to stick with a regular bellhousing though just based on my experience with my Mark's kit. Now, that may not be possible with a 40 due to space constraints.