But after April 66, the 289's got rail rockers. Then in 67 a new head appeared, which was also carried over as the 302 head in 68. Rockers and combustion chamber ccs don't make em fast. Whole point is, what was used on the 289's was also used in the 302 heads. So "Better Heads" is an untruthful statement. Not even the 289 Hi-po's had anything better in port/valve design than the std 289 heads. They came with screw in studs and cast-in spring pockets where the std heads didn't. That was the sum total of the difference.
The 302 is better at making torque than a 289. More torque make more HP at the same rpm. What made the 289 stand out is what it was being compared to and the light weight cars it was put in. The 289 Galaxie was a slug! When you compare a 289 to a 283 it is better because it has more cylinder volume, produces more torque and can rev higher than the old 283. The Mustang was a 2700 pound car - very light! the 289 performed well in it. Our Mavericks and Comets are 3000 pound cars and they need more engine to have the same performance. No engine can rev faster just because it has a short stroke. The engine can't rev (accelerate) any faster than the car it is pushing. A small short stroke engine will not make a 3000 pound car accelerate faster than a larger stroke, bigger engine. The biggest engine (built to the same stats) will always produce more torque and accelerate a car of the same weight faster than the smaller engine. The 302 is as good as any 289 ever made - they are the same engine but the 302 has a longer stroke - that means it produces more torque with the same compression, valves and exhaust. The 302 has larger valves than the 289 - it breathes better! The 289 had 1.75" intakes and 1.4" exhaust - in the 289 HP it produced 272HP with 10.5:1 compression with those small valves and ports. (proof you don't need aftermarket heads to make HP?) The 302 has 1.84"intakes and 1.5" exhausts with larger ports. It has 8.3 to 8.5:1 compression - a cam made for emissions, lean carb, retarded timing, and a mess of other changes made for emissions control. If you built the 302 to the same specs as the early 289s the 302 would make our heavier cars perform as well as the light cars that used the 289. Where engines are concerned bigger is ALWAYS better!
Both the 289 and 302 had the same valves. Only the early 289's had the smaller valves (1.67) these were dropped in mid 1964. The ONLY 302 that had 1.84 intakes were the 90's Cobra 5.0. All others had 1.78/1.48 valves. As for a shorter stroke engine making less torque than a longer stroke engine, that's not always true. A few years back when Car Craft was doing a big block buildup series, the engine that made the most torque was the Mopar 440. It also had the shortest stroke (but the longest rods) The 289/302 cancell each other out in this case. The 289 may have a shorter stroke, but it's got longer rods than the 302. (5.155 vs 5.095)
All i know is i saw a 210hp comet run a low 10 at indy in SS. With enough creative engineering anythings possible ,but i think the 289 has a good rod to stroke ratio and a short stroke.
289s aren't all that. Sounds like those guys just have a good combo sorted out. Put a roller 5.0 in the place of the 289(all other things equal) and those cars will run even faster.
