8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

After thinking it about for 8 years, the swap has begun. My '72 looks good, but it has the original engine in it. The odometer shows 02,XXX miles. I don 't know how many times it has rolled over, but that old 350 is tired. The 8.1 and 4L85 are out of a 2003 3/4T Suburban. The engine has 80,000 miles on it and the tranny has 10,000 miles on i.

I have checked the engine carefully and while doing so, installed a new mid range Comp Cam and lifters. The ECU is off at Howell Engine Development to be reprogrammed.

After assembling parts, the first step was to move the gas tank out of the cab and put it behind the rear axel. I pulled the bed off using an engine hoist and a 4x4 timber "H". Two bags of fertilizer provided the needed balance weight.

The tank is for a 72 suburban. After removing the spare tire brace, it fits right in. The third brace from the back under the bed has to be cut down (up?) to fit over the tank.

More Pictures tomorrow.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Lifting the bed off was a one person operation, with the use of an engine hoist and 4x4 frame.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

This is my plan too, but I was figuring on 2x4 instead of 4x4. Now I'm second guessing that. Short/wide box, wood bed.

I'm looking forward to the progress on this thing. That 8.1L is huge!

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

The fuel tank (from LMC Truck) is installed, ready for plumbing. Couldn't have done it without the excellent help of my grandson, Zach. A significant modification is the addition of an electric, in-tank fuel pump. It is an Airtex 3501M and is the specified replacement pump for the engine/tranny donor vehicle. It is spring loaded, so it fits perfectly (height wise) in the LMC tank.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

I would worry about the 2x4 twisting or bending.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

The bed brace has now been cut to accommodate the tank. I marked the cut line with a Sharpie then cut it out with a cutoff wheel on an angle grinder. Then I welded the bottom of the brace back on. Note the 2" hole in the brace to the right of the bed bolt. The hole is angled up and to the right. It is lined with 2" tubing and both ends are welded all the way around. The filler neck hose will go thru the hole and up to a new door in the side of the bed just behind the left rear wheel well.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

I'm gonna watch this one

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Just a thought but, -- DONT ruin your bed by cutting a hole in it for the filler neck -- put it behind the marker light. I put mine in a stepside and it was super easy, a fleet side will be a little tougher because its a little tighter but definitely doable. Search "gas filler marker light" - there are several threads on here.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Tommys72,
I am looking for input and ideas as well. I have never done a project like this before. Thanks for you service.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

I am working on "the right solution" for the filler door. I saw this truck at the Good Guys show in Tacoma recently and loved it. It sort of makes you say, "did that come that way?". I have delayed that decision while I look at alternatives. Thanks for the ideas!

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Personally I don't think it's "ruining" the bed because there is nothing done by adding the fuel door that can't be undone at any time by a good fabricator.
I agree though that on a 68-72 truck the marker light approach is a good one.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

I have made some progress since my last post. The gas tank is installed, including fuel lines and fuel pump wiring. I may have to move the wiring around when I put the bed back on, but that will be easy.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

While I was working around the back of the frame, I installed some new Monroe Gas Magnums.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

I have also been busy at the front of the truck. The bumper, grille, hood, fenders, radiator and radiator support have all been removed. The old engine is ready to come out.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

I have decided to solve the new engine crossmember problem by purchasing the DIY4X crossmember kit. A link to the product is below. The picture on their website is old. The kit one includes a removable center section. That section is the only thing that will have to be modified to fit the 8.1 oil pan. Here is a picture of one done for a 72 Blazer. You can see that build on the CK5 forum. Look for Igor.

http://diy4x.com/cart/index.php?rout...&product_id=80

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

As I took the front clip off of the truck, space quickly became an issue. I had no where to store the big body parts. I was also concerned that moving them around was going to surely result in damage. The simple solution was to store the fenders, hood and other parts in the bed. I built a wood rack the allowed the parts to be stacked. So far, it has worked well.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Very sharp looking truck.
Great build you have going here.


If you ever need info on the 8.1 swap,
DirtyLarry is sort of a guru on these swaps.He posts alot in the 4x4 section.Very smart guy.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Time for an update. I have managed to make a little progress on this swap. As shown below, I finished installing the new fuel tank behind the rear axle, including the fuel line, return line, wiring for the in-tank pump and a wire to the original fuel gage in the truck.

I also swapped the original vacuum boost Master Cylinder out for the hydro boost MC from the donor 2003 Suburban. It took a little welding and grinding, but in general, it fit in nicely.

Spend some time contemplating my choice to use the original drive by wire throttle body, which requires the use of the also original huge accelerator pedal. After studying the pedal assembly, I determined that it did not need to be huge. the bulk of the pedal assembly is dedicated to the ability to perform an adjustment of the pedal height (in Suburbans with "Driver 1/Driver 2 systems). That feature is not applicable to my 72, to I cut away the unnecessary pedal mechanism and grafted the original pedal onto the now much smaller assembly. It is installed and feels just right.

I also finished striping away the parts on the frontend that were either in the way or being replaced. She is ready to begin reassembly.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Quick update. This build is going slow but steady. The 8.1, 4L85e tranny and NP241C transfer case are all mounted and aligned with the diff. No drive lines yet. Working on linkages and accrssories. Transmission shift is hooked up and works perfect. Looking for a shifter stick for the transfer case so I can finish fabing linkage.

I have run into two issues not solved yet - exhaust and power steering. Stock 8.1 exhaust manifolds won't fit. I tried a pair of new stock spec reproductions of 70's era 454 manifolds and they are not close to fitting. Now I am looking for a pair of good used original 454 manifolds.

Power steering - the truck is a factory air original so it is important to make it work with the new motor. Taking Dirty Larry's advice, I installed the accessory brackets on the front of engine from a 2004 Topkick 4500. That also requires switching to the water pump, harmonic balancer, tensioner, A/C compressor and power steering pump from the Topkick. So far, I have found everything but the power steering pump.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

A couple more pictures. I can't seem to post more than one photo at a time so I'll do a couple of posts.

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Exhaust clearance

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Motor mount and crossmember

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

looking good

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

I have a brand new power steering pump for a topkick hahaha

Re: 8.1L and 4L85e swap into a 1972 Custom Camper 4WD
 

Hey Ed,
Any more updates that is looking good!!!!!

Sean