Talk about a marathon engine.
When talking about squeezing every ounce of gold from a mechanical object, draining the life out of a cast iron block of 1960s technology, Ford's 302 comes to mind.Starting its run in 1968, Ford's 302 entered several of its models and for 27 years it reigned supreme.In the 1980s it was known as a 5.0-liter displacement engine, even though it was 4.9-liters. It was not until 1995 when it finally bit the dust, making room for the 4.6-liter V8 that found its way into Mustangs the following year. Those didn't make an exit for another 15 years.
Ford really knows how to make engines survive. Who knows how long this new 5.0 will last? Back in 1968, the 302 made around 230 horsepower at a not-so-impressive 4800 RPM, while equipped with a 4bbl carburetor. This didn't stack up well against the 427s and 428s, which pushed around 400 horsepower in 1963-64. Nevertheless, Ford took it upon itself to cram this engine in a lot of its models including the hamster-sized Fox Body of the 1980s. In 1995, at the time of its demise, it had become a relic. It still used pushrods, still only made around 200 brake horsepower, had only two valves per cylinder and didn't get fuel injection until 1986 in its Fox Body application.
Lots of people still prefer the 302 4.9-liter engine to the following single overhead cam 4.6-liter, because the parts are cheaper and the engine is more reliable, despite the fact that there are more parts to fail. The 302 was also made with more nickel in its material, which made it stronger.
For all its ancient ways, the 302 was a work horse. Some people reported as of 2004 over 300k miles racked up on their 302s, and that's impressive for any motor. If power was a concern though, there were many options that made the 302 a great candidate for big increases. Two stroker kits were available, which changed the ci to 331 or 347 depending on the kit, which included a crankshaft, rods and pistons. What the kits do is increase the stroke of the piston. For around $4,000 a stroker kit can be had, and would increase the horsepower to over 300, according to some marketplaces. There are many schools of thought, but basically a 347 is assumed to be the most displacement you can get without having to machine the block in any way.
Even then the stroke is so far it puts oil rings at risk. This is thought to be one of the reasons that 331 kits were made. It's a safe bet, and still making over 300 horsepower is a 50 percent increase from the original 1968 specs. At this point though, if you have the money for a $4,000 stroker kit, it might be worth it to pony up the extra $2-3,000 and invest in the new 5.0-liter crate engine.