Converting a 6 Cylinder 65-66 Mustang To V-8 Engine
There are a lot of variables involved in that swap. DO you already own an engine and tranny for it? What level of buildup do you want for the engine, as-is, stock rebuilt or performance rebuilt, or full boogie. at any rate, figure a minimum of 200 to buy a worn out 289, 1,000 to rebuild the engine, 200 for a junkyard c-4 automatic transmission 200 for exhaust work, 100 for motor mounts, 250 for front end steering parts, 100 for a used 8" rear axle, 150 for a drive shaft and u-joints, 100 for used front brakes with 5 lugs, 200 for brake rebuild, 100 for some used 5 lug wheels, and new tires are extra if you don't have 14" wheels now. Add about 30 for a used v-8 accelerator rod/auto transmission kickdown, 150 for hoses, filters and oil and coolant, 300 for all the little miscellaneous stuff you will want/need to change "while you are in there", and another 200 for a new radiator. THIS ASSUMES YOU WILL DO ALL THE LABOR YOURSELF AND THAT YOU DON'T INSTALL/BUY ANY HIGH PERFORMANCE STUFF. You do the math. I would sell it and buy a v-8 car, unless it was your grandmother's car and has sentimental value, in which case you should probably just leave it alone and put your money into a nice stereo.
Bottom line. It would be much cheaper and you would have a car with matching numbers if you sold yours and bought a v-8 car. 6 cylinder cars are known as "T" codes, which refers to the fifth digit in the serial number. 289's with 2 barell carbs were "C" codes and 289's with 4 barrells were "A" codes. High performance 289's were "K" codes. Look at the fifth digit in the number on your driver side engine compartment panel under the hood. You will find something like 5F05T_____ or 5R05T____ where the "T" denotes the engine the car was originally equipped with.
Case in point: My 65 coupe, a very straight "T" code car that the previous owner took immaculate care of. He paid me to change it to all V-8 drivetrain. I installed a 289, a C-4 automatic tranny and a v-8 rear axle and a set of 5 lug, 10" front v-8 drum brakes. When he got through with it, he could not sell it for near what he had in it because the 'T" did not match the v-8 under the hood. ("T" code cars typically do not bring much money to begin with as demand for them is not high) He wound up selling the car to me for $3,000.
If the car had been a "C" or an "A" code, it would have easily sold for $6,000. If it were a "K"code, it would have brought probably $15,000. (No, you can't change the lettering on your inner fender - it is illegal.)
Here is what I would do, in order to NOT throw away a bunch of money on a car that you will NEVER get the money back out of. Enjoy the car as it is (and the cheaper insurance rates you will appreciate) for a year or so until you get your driving skills honed. Imagine that you are spending money to hop up the car, but instead stick it in the bank, letting it earn interest. When you have saved enough to buy a 289 and a new tranny and new brakes and rear axle and etc, etc, etc, THEN sell the "T" code and buy a REAL NICE "C" code with the money you saved plus whatever you can sell your car for. A big advantage to that is that you can actually have fun DRIVING your "T" code rather than laying under it trying to convert it to something it is not. You can then enjoy having a nice "C" code (maybe even get lucky and find an "A" code car) that will likely have power steering and some other niceties. From then on, whatever money you decide to put into the car will very nicely return to you if you sell the car.
