10 years ago I purchased a 1968 Ford Mustang. The previous owner (unsure of his actual position in ownership) told me the car had the original 302ci engine, which had only been overhauled once, and C4 3speed automatic transmission. The car was in very good shape and at the time the motor was solid. I drove the car regularly, kept up with the normal routine maintenance on it, added a couple of headers, and had no problems. Until 6 months ago I was driving home on the highway when the car suddenly lost about 50% of its power and was making some horrendous noises. I limped the car home, less than a mile and parked it. After pulling the valve covers off found that one of the rockers arms was busted and a bent pushrod.
So I pulled the engine apart somewhat, replaced all the lifters, the bent pushrod and both rocker arms on that cylinder. Everything was fine for about a week. Then it seemed to happen again. So the car was parked for good at that point. I never wanted to use the car as a day to day driver which i was at the time, so i purchased a truck and let the car sit for the last 6 months. This weekend i pulled the motor out with the intention of a complete rebuild. After getting the engine out I noticed the casting number on the block was from 1965. I thought this was a little odd considering Ford never put out a 302 until 1967. After decoding the VIN for the car it confirmed that the original engine for the car should have been a 302.
After pulling the intake manifold there was another stamp on the block, 289. As well as inside the headers. I started to have doubts that this was the original engine. After flipping the motor and exposing the crank it was confirmed. What I had was a 1965 289ci engine. Not the 302 that should have come with the car. So when I purchased the replacement rocker arms for a '68 302 they were of a different style and cause the retaining clip on the valve spring to fail, dropping the valve down onto the piston and permanently jamming the valve in place. The block is already bored 40 over and I am unsure if it can be honed out and reused yet. I need to get better measurements to be sure.
So here is the dilemma, should i take the the time and effort to try and restore the car to its original condition with a 302 block cast in 1968, purchase a used 302 block from any era, purchase a new 302 block or just fix the one I have? I leave this decision solely to the good people here at the FES.