Astro 350SS
A Work in Progress

Pics to follow. THis is text I wrote up at the time of the swap: Will be updating shortly
I bought this 1990 Chevy Astro Conversion van with a blown up 4.3 v6, and a bad transmission. I pulled the v6 out and installed a 350 chevy small block V8 in its place. The Swap was very easy with the only non GM parts being the motor mounts which I purchased from JTR (Jags that Run). I swapped the PROM chip with one out of a 90 1500 series pickup. I am running fuel injection, cruise control and A/C. Mileage averages about 19mpg. In the pic above, I used my computer to see what it would look like with 454SS pickup wheels on it. Currently, I am running factory aluminum Suburban wheels on it.

This is what she looked like when I first got her

The first thing I did was to remove the grill, radiator and A/C condenser. You have to have it evacuated properly so that you don�t release Freon into the atmosphere. I removed the compressor with the condensor still hooked up to it. Best to have as few openings as possible to contaminate. Then came the radiator core support. On my van it came detachable from the factory. Newer vans of the same body style have to be cut, but there is a kit that bolts it back in place- I believe from Chevrolet. New style vans (95 and up) have to drop the sub-frame to remove engine, as I understand. I disconnected all the wires, marking them as I went. Most of them have dedicated plugs, but it helps seeing them labeled instead of trying to figure out where the correct plugs go. I then pulled off the accessory brackets, with accessories still attached to them. Disconnect power steering hoses at steering box. I put the front tires of the van up on car ramps. It was a very tight fit for the engine hoist, so I removed the intake manifold with tbi on it. I installed the lift chain at opposite corners of the intake valley as low as I could. This gave the room I needed. I pulled the v6 out, (pain in the hind end) and cleaned up the engine bay. I don�t have any pics of the bay while the engines were out.

I left the transmission in place. Hooking the 350 up to the hoist the same way, I left off all of the external components except the flywheel, oil pan, and timing and valve covers.
With my friend inside the van guiding it to the transmission, I slid the engine into place and bolted it to the transmission. Then I attached the motor mounts to the engine, loosely, and settled the engine into place. Once the long mount bolts were slid into place, I tightened everything up.

Motor mounts are from Jags that Run or JTR. On line at JTR

Here, I have the front wheels up on car ramps. This allows the right angle to slide the engine in, without intake, accessories, or exhaust. This is a view of setting engine in place. Notice I did not have to remove bumper and valance panel below grill.

You can see here how I had the lift chain hooked up. Notice how much room there is.

.This photo shows how far back the engine is sitting in the van.As you can see, the front of the engine is under the firewall. Plenty of room.
Once I had it bolted in place, I started mounting the accessories, intake and exhaust manifolds.

Here I have the accessories bolted on. These are strait off of the 4.3 v6. You can see how much room there is above the tbi.

This was my one area of concern. You have to loosen the brackets on the a/c drier. If you don�t, you will break the plastic box it is mounted on. (Found out the hard way.) . Once loose, gently bend the drier forward. If you don�t do this, the alternator will hit the drier when the engine torques up (also found out the hard way).

Now the fun begins. Some of the things that you have to change when doing this swap are the injectors and fuel regulator in the tbi unit. You need them from a 350. I got the intake and throttle body for $50. The tbi I picked up was a little worse for where, but the injectors were in good shape. 3 screws hold them in place on top of the unit. You will also need a v8 distributor that is similar to the v6 one. All the plugs are the same. You will need a cruise control/ T.V. cable / throttle cable bracket. Also the coil bracket, and other intake brackets from a v8.
NOTE: Best parts are from similar year full size Chevrolet van with same engine set up that you are going to be using. This is for intake brackets only. You will be using the accessory brackets off of your 4.3.
NOTE: If you are swapping from a 4 cylinder to a v8, there are plenty of 4.3 v6 vans in the pick-a-part yards. Older style brackets are probably a little harder to use but best to get them off of similar year van due to a/c compressor changes.

Now the wiring begins. It looks like a complete mess, but it is actually quite easy IF remembered to label the wires and hoses before you started.

The other things you will need are same full size Chevrolet pickup 350 exhaust manifolds, and the PROM chips and/or ECM. You can use your stock radiator and hoses, although the lower one has to be cut and shortened. A better way would be to get flex hose in the correct length. You must use a fan shroud. You can cut your original one back to work. Be careful because they are brittle and crack easily.

In Conclusion: This is how I did my swap. There are a couple of things I should mention. It is a good idea to use a new transmission designed for a v8, or rebuild yours to v8 specs, or get one out of a v8 Camaro. If you get one out of a Camaro, you will need to install a shorter drive shaft yoke because the splines are shorter on the out put shaft.
I highly recommend on deciding how much power you want before you start this project. I originally chose this setup for towing the family and a 5000lb travel trailer. This engine is a stock replacement GM crate motor. Since completing this project, we have gotten another tow vehicle (96 Astro w/ Vortec V6) and now I desire more horsepower. If all you want is a fast hot rod, or if you are going up there in horsepower, you might consider going with a carb. I did it this way because it was going to be the family vehicle and I wanted good gas mileage and dependability. By the way, I average around 17-19 mpg. All in all, it is the easiest swap around, and the mouth dropping looks are worth it. No one expects a little puny Astro van to whip them at the light!! Can you say �Sleeper�?