64-66 Ford Mustang 6-Cylinder to V-8 Conversion

When I was 16 years old I received a 1966 Mustang that was a 200 cubic inch 6 cylinder. Well that engine didn’t last too long before it blew a few rings and cracked the head. I then decided to “swap” it to a V-8. So I have decided to put this paper together describing some of my experiences, costs, and troubles that went along with this 18-month project.

First off, I started by tearing everything out of the powertrain. I took the radiator, battery, engine (starter, alternator, etc.), transmission, shifter, driveshaft, rear axle, and the entire front suspension out. I then taped off all the electrical to protect it and sanded, power washed, degreased, and repainted the engine compartment and undercarriage of the vehicle. At this point the vehicle was up on blocks and looked like a mess.

My next decision was to figure out what I was going to do as far as the suspension was concerned. I ended up replacing the entire front suspension, which included the upper & lower control arms, spring insulators, springs, perches, shock absorbers, sway bar, strut rods and strut rod bushings. Next I moved on to the steering components, seeing that the 289 components are a little more heavier duty than the 6 cylinder they had to be switched out. They pitman arm on the steering gear box is a different length, so that had to be taken care of. Along with changing the location of the idler arm, and installing a new draglink, inner and outer tie rod ends. Thus, I could now steer the car.

My next concern was to try and get the car down off the blocks back on it wheels, that way I could manage to get it out of the garage when needed. I then ordered a disc brake conversion kit, which was manufactured by Stainless Steel Brake Corp. I had to then scour through the junkyards to find myself a set of front spindles. These were easily found within a couple of days and installed. I then put the new brake system on the front, in which I installed new steel brakes lines from the new master cylinder down the caliper area. I next purchased an 8-inch rear end (stock 289) and installed this in the rear of the car. Thus, I now ran new brake lines to the rear brakes, proportioning valve, and installed all new brakes, drum to wheel cylinder, making sure I will stop. Now the car was in a “moveable” state, in which it sat for awhile.

All along I had in mind putting a pretty stock 289 in the vehicle but this changed when I went to the engine shop. My cousin worked at one in the Los Angeles area, when I arrived I was influenced into buying a 302. Then to later up it a little bit more by putting aluminum heads and so forth on the motor. All in all this has been a strong engine and I am very happy with it. Next was getting some pulleys, which I ordered from March, and motor mounts for the 6 cylinder frame mounts, luckily the local mustang shop was able to supply me a very acceptable set they had on hand and I was on to the next dilemma. I took the transmission down to my neighbor’s transmission shop and explained my situation and what I had in mind. He took it from there and I returned to pick up a nicely built C-4 including torque converter and bellhousing.

Installing these two items, engine and transmission, wasn’t very hard but it had a few snags here and there. I had to do a little massaging to the transmission cross member and mount, but it went in finally. The exhaust headers were a little fun to get in, seeing I didn’t bolt them up before dropping the engine in, make sure you don’t make that mistake yourself. After hooking up all the transmission cooling lines, radiator hoses, radiator, all engine electrical, electronic ignition, relocating the battery to the trunk, running new fuel lines, flushing the fuel tank, fan, shroud, oil sender, temperature sender, electronic fuel pump, fuel pressure regulator, etc. She was on the brink of being running. I decided on a new B&M shifter, which required a little bit of cutting, running some wires and installing some bolts, which took an extra day. On installing the driveshaft, I had it made to the measurements I took off the car with the transmission and rear end installed. After installing the driveshaft itself I checked the pinion angles to make sure they were in the “safe zone” before running it. Lastly, I threw on some tires and rims that I really wanted on there, and decided it was the moment of truth.

The break in period was pretty much done by the engine shop before they released the engine to me so I wasn’t to worry on that. Also the timing was set good enough to get a decent idle out of the engine. So I took it and dialed it all in as best as I could to get it to the muffler shop. After having the exhaust welded up and had my mechanic do an inspection/tune up on the vehicle I had pretty much accomplished my goal. There are many little items you will meet across along the way that I haven’t listed in this paper such as cleaners, nuts and bolts, rubber hosing, etc, which will increase the cost of the project. But, if you attempt this process it has tons of knowledge that you will hold on to forever. On top of that you will know your car inside and out and have the feeling of certain that the vehicle was done right and most of all its YOUR car!

Written By:
Steven Adelmann

Click here to return to Mustangsandmore.com