300 Cubic Inch Canadian 6 cylinder Truck Motor
Bore & Stroke: 4.00″ x 3.98″ Compression Ratio: 8.0-8.9:1
1965-1972 Brake Horsepower: 170 @ 3800 rpm Torque: 283 lbs.-ft. @ 1600 rpm
1973-1974 Net Horsepower: 101 @ 3000 rpm Net Torque: 223 lbs.-ft. @ 1600rpm
1975-1977 Some were the same as ’73-’74 others were bumped up to 120nhp @ 3400 rpm with the same torque specification.
1978-1986 Horsepower ratings varied from 101nhp, 115nhp, 117nhp and 120nhp @ 3000-3400rpm. Torque ratings remained 223 lbs.-ft. @ 1600 rpm.
1987 – 1993 Switched from carbureted to electronic fuel injection. Compression ratio was 8.8:1 Brake Horsepower: 145 @ 3400 rpm Torque: 265 lbs.-ft. @ 2000 rpm
1994-1996 Brake Horsepower: 150 @ 3400 rpm Torque: 260 lbs.-ft. @ 2000 rpm
Air Intake: Most people seem to like K&N’s, but any filter open 360* is an improvement over stock.
Carburetors: A Holley 390cfm 4bbl is the most popular choice and works best especially with stock cam, a lot of people are happy with 500cfm Edelbrocks too though. Only use a 4bbl with an Offenhauser or Clifford 4bbl intake, use a 2bbl with an adaptor plate.
Intakes: Both Offenhauser and Clifford make a 4bbl intake for the 300. Offenhauser seems to be the favorite because it’s cheaper and just as good. Clifford makes 2 and 3 carb intakes also.
Headers; Headman and Clifford are both good choices, of course Headman is cheaper.
Camshafts: Both Clifford and Isky make a wide range of camshafts.
Ignition: Any performance ignition, MSD is most popular.
Heads: You can have porting; polishing, bigger valves also putting on a 240 head will raise compression.
Exhaust: High flow mufflers, dual cats, no cats, hollowing out cats. 2 1/4″ True duals with split headers is suppose to work the best.
Electronic Fuel Injection
Same kind of stuff except instead of slapping on a bigger carb, since fuel injection doesn’t use one, duh, you’ll want bigger injectors and maybe you can find a bigger throttle body that will fit.
Turbo: Some people have had custom manifolds made and used the turbo of Chevy diesels; there are no kits for this so it would be a custom job.
Chips: To my knowledge there are no performance chips for the 300.
Ford’s 300 inline 6 is a fairly problem free engine for 200,000 to 300,000 miles if properly maintained. Common problems with the carbed models are vacuum leaks, just little ones can cause hesitation, rough idle, etc. The stock Carter 1bbl carb seems to like rebuilds too. On the automatic transmission models some people have problems with overheating, this can be fixed with a cross-flow radiator and flex fan or a electronic fan. Besides that if they’re over revved the 300 is known to throw rods or have early valve train failure.
I am not very familiar with the fuel-injected models so I don’t have a whole lot of advise to offer with them