to start with you need to mount a pair of laser pointers to the wheels. They need to be spaced away from the car enough so they clear all the bodywork. The alignment of the pointer parallel to the wheel does not need to be precise. My setup was pretty basic. I used a bungee cord that was tied up short across some of the holes in the rims. These cords were holding a scrap of wood and the laser pointer.

I did the same thing on both sides of the car and adjusted the steering to get them close to pointing straight back behind the car. I then put a 2×4 on some stands for a target about 30ft behind the wheels.

I put a line on the board where the lasers hit it. I moved the board a bit so the picture would show the line a bit better. I drew the lines directly through the center of the dots.

After making the marks, I moved the board 30ft in front of the car and rolled the wheels half a turn so the pointers were pointing forward. I lined up one side with the mark. Since I replaced the passenger side inner tie rod I lined up the drivers side line. I then marked the board again on the passenger side then made a target mark centered between both marks. I then adjusted the tie rods to hit the target mark. I rolled it back and forth a bit to keep the wheels from binding. I made sure not to let the drivers side wheel move and kept turning the wheels to keep it pointed at it’s mark. After I got the laser to exactly on the target line I put it 30ft behind again to verify it was all good.

This gets the alignment incredibly close. As long as the board is square to the front and rear of the car your alignment should be every bit as good as any machine can do. If you want more precision just set the board out at a farther distance from the car. The great thing about this method is that it does not need the laser pointers to be aligned well. Since they are not being touched they will be accurate front to back even with a bent rim. Most production cars have a small amount of toe in so if you want that just set the front points to be about 1/16 inch narrower than the rear to give it a degree or two of toe in.

I still have to paint the running boards and remount them and I have to repaint the window trim and door handles black. I will do that in a few weeks after the paint has dried good and I can buff it out to get a real deep shine. But for now it is painted and looks good.

After putting the primer on there was almost nothing left that needed fixing so it only took a few minutes to fix the flaws and then wet sand the whole thing before putting the paint on.

Edit: Added pictures with the running boards installed.

Pictures with it mostly complete for the winter.

The hardest part is getting the old stripes off. I first tried using decal remover on the passenger door. I used about half a can of aircraft decal remover getting most of the upper stripe set off. I then sanded it down until I got it smooth and no trace of the stripes showed through the primer. It was going to take me forever to sand the whole thing down so I switched to paint stripper. With the stripper I managed to remove all the stripes and the paint below the stripes in one day. I have half the body work done on it. The hood was beat up pretty badly and there was a rust place on either back wheel well that needed patching. The rest of the body didn’t have any rust or damage at all.

The running boards are off and will be painted separately before putting them back on. I have to smooth the edges of the paint that is still on the van before I can prime the whole thing and repaint it. I am just painting it back the same color and will either restripe it later or find a mural to go on it. But for now just getting it painted and nice looking is all I am wanting.

So here it is. It almost looks stock the way all the hoses and wires are ran.

The last picture shows where I mounted the Glow Plug light and the Water in Fuel light. Those are the only things I needed to add to the dashboard.

Here is a video put together showing how it runs. It has more power and better mileage than the stock 4.3L engine. I am very happy with how it has turned out.

If anyone wants to do this swap here is what I recommend.

Get the factory service manual for your van and whatever van you get for the swap. Keeping them in the same year range will make life much easier. I did a 94 Astro and 94 G30. It is just way easier when you have a question to dig for a few minutes in the manuals than to have to search and ask questions on message boards.

There is probably no chance of getting the motor in the front so don’t bother trying and just drop the subframe.

The V8 motor mounts will make things easier but you should still bolt the 6.5 to the stock trans and stock trans mount to get it all sitting square on the subframe. The starter will need a hole cut in the crossmember to keep from hitting. Also the oil pan is closer than it should be and rubs the crossmember just barely. So bend the front edge maybe 1/4 inch where it is close. When you test if it together you will see what I am talking about. Also bolt the starter on now. When it is in the van it is very hard to get to that little brace on the back. You must use that brace on a diesel or the starter will crack the engine block. Just run the battery wire to the front out of the way somewhere and as you are lowering the van connect the small starter wire. I have big hands though so if you have small hands it isn’t quite that bad to get in after it is installed.
The stock trans mount can work just drill new holes and bolt it where the 4l80 puts it. One bolt will go right under the body bushing so I cut it to clear and welded on a small tab to get a second bolt in there. A flat head bolt would probably also work fine.

Before putting the subframe back on:

Take off the parking brake bracket and put the rear bolt back in and leave it a turn or so out from tight. Take the same bracket off the passenger side and toss it. The parking brake bracket needs the bolt hole notched so you can slip it over the bolt already in there. Also one side needs ground down to keep from hitting the crossmember and transmitting vibration. The crossmember sits directly over the rear bolt so if it isn’t in there before the subframe is mounted it isn’t going to go back easy. Just slip the bracket on and tighten it with a wrench after the subframe is installed.

The ABS module bracket needs cut and moved over an inch or so to the drivers side to get the module to clear the valve cover. Get it as close as you can to the steering without hitting anything else. This would probably be very hard to do after the motor is in without a plasma cutter or some way to cut it without cutting the firewall right under it. With the motor out it is an easy job to move.

After the parking brake bracket and abs module are adjusted then you can put the subframe back under it. The body just barely hits the drivers side injector lines so bend it slightly. As you lower it down you will see what needs adjusted. Don’t get carried away and deform it though so the doghouse will still fit on easily.

The Astro Y pipe will work good enough with a slight tweak to get it to fit but it is kind of small so it should be replaced. Make sure the cat is off it or you wont get far before you break lots of expensive engine parts.

The wiring is going to be dependent on the years so that is why I say get the factory service manuals. They are cheap on ebay if you look around. But on a 94 it was pretty easy. Just keep the water temp wire and oil pressure wire and the single fuel level wire out of the engine harness. Everything else including the computer comes out. The 94 G30 computer goes in and all the colors match up to get it working as long as you have a pin out to see what wire is what. The non turbo 6.5 engines have no computer so they only need the glow plug power and the fuel cutoff solenoid wired to run. The 4l80e needs the computer and won’t run without it.

Some G30 vans have a slip yoke on the trans and some have a bolt on. If it has a bolt on just order the slip yoke for one like a 97 short wheel base. Also you need a conversion U-joint to go from the stock driveshaft S44 to the yoke’s 1350 size.

Overall it really isn’t a hard swap. The wiring might scare some people but the required wiring is pretty basic. I don’t think it is much harder than a 350 swap really. I figure it would probably take only slightly longer than a 350 swap. Most of the extra time is just the other stuff like changing the fuel tank pickup tube out and sorting out the wiring to keep it looking factory. Getting that split loom stuff on it takes some patience.

First thing was getting the fans on it and the final tweaks to the radiator position. Once the position was figured out and the last bits of metal that were in the way were cut and nothing was going to rub against the radiator then it was just a matter of bolting the fans into place. After that the two transmission coolers and the engine oil cooler could be mounted and the grille put back on.

There is plenty of space between the fan and the water pump. At least if you consider a half inch plenty of space.

The shifter rod needed a bit of adjustment with a sledgehammer to bend the bracket an inch or so back. It would bind when going lower than OD and it was impossible to get it in 1st gear before bending it. The doghouse took a little bit of effort but it was mainly just get the side that needed bent a little bit back to the right shape so it would slide over it. The problem with the battery isolator was found and fixed so now it charges all three batteries but when it is on accessory it just runs off the deep cycle battery in the back. It starts on the two primary batteries like any other diesel.

It is pretty much ready to drive now. I need to make a shield for the battery under the body to keep road spray off it and put the spring expanders on the front springs to get it sitting level again. Other than that it is complete and just needs washed and vacuumed out. If I can find a truck water neck to make the upper hose lay in the right place it will even look totally stock..

If the weather gets a bit better I will clean it up and get some final pictures of everything as well as some videos of it driving. So far the forecast calls for a nice day Thursday. We tried making a video tonight of it but the rain was making so much noise on the metal roof it was hard to hear anything other than the rain.

I went back to the G30 alternator and swapped pigtails so it would plug in and work the idiot light on the dashboard if it ever has any problems. The alternator I was using on the Astro 4.3 motor just quit working so instead of waiting to get it replaced I just used the G30 alt. The dead alt is under warranty still so I will exchange it and keep it as a spare.

I also found a radiator that seemed to be the best candidate for swapping. A radiator for a 67 suburban has the transmission cooler and is a 28×17 core. It has about the same hose sizes and fittings as the stock G30 radiator except for no oil cooler on the side. The G30 radiator has a 32×19 core and won’t fit at all. I got the radiator down in the stock location but that put it pretty close to the pulleys and I would only have a quarter inch of clearance from the fans to the motor. There is more room in front of the radiator to move it forward so I cut away a bit of the metal that was in the way. I could then move it right up behind the condenser. There is now plenty of room behind it for the fans and a bit more air flow. I will have to trim the radiator support across the top but not that bad to make an opening for the cap. It should work out good where it is at.

I will have to move the two transmission coolers and make room so I can get the engine oil cooler mounted in there. I will try and finish mounting it and get all the hoses hooked up tomorrow.

Today I had lots of little things to do. I had to adjust the throttle position sensor to get rid of a code on the computer. The stock G30 air filter won’t fit under the doghouse so I had to put together a combination of pieces from both air filters. I cut the snout off the stock Astro housing and used it. The opening on the G30 housing was really small so the Astro one should offer more air flow. After that I reconnected the brakes and added fluid with the bleeder valves open till they started dripping to get the system primed. While the fluid was working it’s way down the brake lines I started putting the exhaust together.

I had all the pieces from the G30 and the Astro exhaust to use for parts. I managed to use mostly the larger G30 pipes and muffler to get it done. I have the Astro Y pipe on it for now since the G30 pipe comes out on the drivers side. I will have a 2.5 inch Y pipe made and a good 4 inch exhaust put on it later. But for now this one is good enough to drive.

If I can get the alternator working tomorrow and a few minor things I should be able to get it out and drive it and see if the transmission computer is working properly. If the transmission computer is good then I should be real close to putting it back on the road once I find a good radiator for it.

First thing was getting all the accessories fit onto the front of the engine. It all fit but there isn’t much room to work. It really isn’t much tighter than the 4.3 it used to have but everything is closer to the radiator.

I had to use the stock astro radiator for now. The hoses are a bit of a mess but they will do until I get a good radiator made for it. The main thing is it is for the most part complete and ready to run.

So with everything buttoned up and all the fluids topped off it was time to hit it and see how it runs.

The first video is of the very first try of getting it to start. It started pretty easy but there wasn’t enough fuel in the lines to keep it running while it picked up prime from the empty fuel lines. It only ran a little bit on the fuel in the filter before dying.

After that we had to manually prime it by taking the fuel filter out and pressurizing the tank to blow diesel up through the lines to get all the air out. Once we did that it started up without any more trouble.

So now it is running good. There are still a lot of little odds and ends to get done but it is pretty close to being back on the road. If I can get the few parts I need this weekend I should be able to drive it soon. But being a holiday I bet it will take till Monday till I get the parts in to have it complete.

T here is enough room to fit one battery under the hood but not enough for both of them so I had to mount one battery up under the body. I ended up fitting it right beside the transmission. I used the battery tray from the G30 and cut it to fit in the opening I had available. I had to add a few more brackets to make it solid. It is now mounted and the heavy wires are ran back to it. I still need to make a cover for it to keep it from getting soaked every time it rains but that is easy and I think I already have something here that will work for it. I am not worried about it for now though I just want to get it running to make sure it is not going to be in the way before I bother with it.

With the batteries sorted out I turned to the wiring. I have already cleaned out the astro engine harness and removed the gas engine’s computer. So the only parts left of the astro wiring were to the dashboard gauges. I cleaned up the G30 harness of the non engine wiring and put it in the van and started combining the wiring and getting everything hooked up. I have the factory service manuals for both vans so it was pretty easy just tracing each wire and joining them up. Since they were both 94 models all the wire colors matched up as well so that made it even easier.

With the wiring done it is getting near complete. Still to do are the exhaust and all the engine accessories as well as the radiator. After that it should be real close to driving.

Getting the frame patched wasn’t that bad. I just used the old bent flex plate for the patch metal. It had holes in it that were a perfect match for the bushings to go through. So I cut a bit off it and welded it onto the frame. I just spot welded it on top and bent it over the sides to hold it solid. I didn’t want to weaken the frame by welding it all the way around it. I undercoated the frame good to try and keep the rust from getting to the places where bolts were removed and there were bare spots. It has made it this long without bad rust so a little bit of undercoating should get me another 16 years out of it. I think the front corner is rusted worse than the rest of it due to the battery being over top of that area.

After that was done and while the undercoating was drying the tank was dropped and the sender and pick up tube off the G30 tank was fitted on it and it was put back up under the van. I need to run new fuel lines, the old ones are pretty rusted and are in the wrong place. That should be easy to do though.

With all that done it was time to get the subframe back under the van. It took a bit of effort to line it up but it wasn’t that bad. I watched to make sure everything would clear while a buddy lowered the body down. The only parts that didn’t clear were the abs module needs moved over about an inch to the side and the lip of the doghouse drivers side opening needed bent over about half an inch or so to clear the fuel lines. Other than that it dropped right down like it was made to fit. It took a bit of fiddling to get the frame lined up and bolted back down. But now it is sitting solid with it’s new motor in there.

Next up is hook up the driveshaft and fuel lines. Then start on the big mess of wiring. I have a ton of wires that need removed from the Astro harness. The last few things are put all the accessories back on the motor and figure out where to mount the batteries and get the radiator fit down in it somehow.