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Installing a Chevy V8

Note: I have not had this car since March of 2005 and it's been much longer than that since I last worked on it.

DISCLAIMER: This document does not cover all of the operations needed to completely convert to a Chevy V8. It is an outline of the major steps needed to perform the swap. This process exposes the installer to significant bodily harm due to the weight of the components and the tools involved. The author assumes no responsibility for the outcome of this operation.

As you may have guessed, swapping a small Chevy into a non-GM car is not exactly a simple matter. This is not to say that its impossible or even extremely difficult. There are a few things that you need to be aware of, though. First, the small block Chevy weighs less than a factory V-8 (287 or 327). What this means is, if you just put new springs on the front of the car, it will sit higher than stock and, an adjustable proportioning valve may be needed to maintain proper brake balance. I haven't gotten that far on my car yet, but I will let you know what I ended up needing to do. Second, the factory speedometer cable will not work. Third, you will need to re-wire the engine compartment because all of the electrical components are in different places.

Note: Whenever you take on a project of this scope, you will need to remember one critical thing: measure twice, cut once. It is much easier to remove metal than to add it. Just fitting the crossmember for the engine, I had the engine in and out of the car 10 or more times and I spent four or five hours doing the final fitting before I even started to weld. You should also get a factory level service manual for the model you are working on that has all the different frame measurements in it. Most cars have the engine offset to the passenger side. The goal is to get the new one in the same position.

WARNING!  This process involves cutting and welding. The tools used for these operations can be extremely dangerous if misused. Always wear safety glasses and when welding, wear an approved helmet with the properly shaded lens. Make sure you have a fire extinguisher close by. If you get stuck on a step, STOP! Get advice from someone who is familiar with fabricating chassis.

The best way of doing this in an organized manner is to lay it all out for you. Also, keep in mind that it is not possible to detail every step needed to do this swap. Each car will be slightly different due to year to year changes and equipment differences. So, with that in mind, get out your tape measure, a plumb bob, some string, and your chalk, and follow along:

1. Degrease the engine compartment, drain all fluids (including the gas tank), and remove the radiator.
2. Find the centerline of the motor and make marks on the firewall and radiator core support.
3. Make a note of how all of the heater hoses are connected. Do the same for the wiring.
4. Take a few pictures of how everything looks now.
5. Disconnect the wiring, hoses, etc and remove the engine and transmission and set them aside. Make sure you remove all of the brackets for the transmission mount.
6. Inspect the engine compartment for rust and fix anything you find now. Its much easier with the engine out of the way. Also, check for cracks in the shock towers.
7. Find the center line of the new engine and make a mark on the back of the intake manifold. You can use the balancer bolt to line up with the mark on the radiator core support.
8. Decide how you are going to mount the engine. You can use motor mounts from a `69 GM pickup and make adapter plates, an engine crossmember, or street rod style brackets.
9. Put the new engine and transmission in the engine compartment. Line up the center marks you made earlier, level the engine, and make sure everything fits (make sure to check around the steering gear). Early Ramblers have narrow transmission tunnels.  You may need to modify it to get your transmission installed.
10. If you are going to use truck motor mounts and adapter plates, install the motor mounts and measure for the adapter plates.
11. If you are using a crossmember, measure for width and cut to length. Also, you will need to notch the end brackets and shock towers to move the engine back far enough (click here for a drawing of what to cut. You'll need to remove the steering shaft to cut the drivers side. On my car, this meant removing the steering box.). Cut the mounting tabs off of the crossmember and the bolt tubes off of the tabs. Install the crossmember in the car and position the hoop to clear the steering. Tack the brackets to the crossmember. Bolt new tubes to the motor mounts. Attach the mounting tabs to the motor mounts and line everything up again in the engine compartment. Tack the mounting tabs to the crossmember and bolt tubes. Remove the crossmember and do the final welding. Reinstall the engine.
12. Measure for the transmission crossmember and cut to length. Assemble the crossmember and install in the car. Mark where the holes for the brackets need to go and install riv-nuts. These will allow you to remove the transmission crossmember. Bolt the crossmember into place.
13. If you are using an engine crossmember, you will need to switch to a short style water pump. Install all of the accessories, the exhaust manifolds or headers, the radiator, and the fan. Check clearance with the steering gear and car body.
14. Fabricate the throttle linkage. There are several types available (solid link, cable, and hydraulic) so the details will vary depending on what you choose. Make sure you check 3 things. First, make sure that the throttle returns to the idle position. Second, make sure the throttle plates are straight up and down with the gas pedal all the way on the floor. Third, make sure that the linkage works without binding.
15. Hook up the heater and radiator hoses. DO NOT use the cheapo accordion style heater hoses. They restrict flow and will make the car run hot.
16. Reroute the engine wiring. Make sure that you remove the resistance wire (this is a pink wire in the harness going to the coil) or ballast resistor from the distributor wiring if you convert to HEI.
17. Fabricate transmission cooler lines. Consider an external transmission cooler. They work better than the factory types. A cool transmission is a happy transmission. Make sure to hook up the speedometer cable.
18. If needed, reroute the fuel line. Try to limit the amount of neoprene (rubber) fuel hose in the engine compartment to 12 inches. You can use as much braided steel as you want. Make sure you have a fuel filter installed. If you are using a Q-Jet, get rid of the internal filter and install an inline one.

That's all there is to it! Remember to take your time and measure carefully.

Last Updated 08/17/08 03:37:58 PM