I know the 302 has a longer stroke and shorter rods.... I screwed up on the compression height issue - You are correct I got the boss 302 mixed up in my mind with the standard 302. The Boss 302 has shorter compression height and uses the same length rod as the 289. For some reason I mixed it up in my mind thinking the 302 had a shorter compression height too. That was wrong - standard 302 and 289 pistons are interchangeable and the 302 does give up the rod length (all .065") due to its longer stroke. 5.155 inches for the 289 rod and 5.090 for the 302. 289 ratio is 5.155/2.87 = 1.796 302 ratio is 5.090/3.0 = 1.697 just under six percent difference. It probably loses some of the power over the 289 because the slight angular difference of the two rods but gains much more with the 4.4% increase in cubic inches and the longer torque arm (4.5%) of the crank.
ya paul i did the math on that to, good for you to step up. now i have six months to put the xmas tree together can,t do it
OK, I've got a question here......I have a engine I traded for recently, was told it was a 289 from a 67 Fairlane. It has a D5 block casting, which I assume is a 302, so I know it is not original to the Fairlane. The crank though, is a three bolt front pulley, which should be a 289, right? So what is it? A 302 or a 289?
It's definitely not original. One way to tell is to pull the pan and look at the casting numbers on the rods. I don't know what year Ford went to the 4-bolt pulley cranks, but if it's a 289 crank, it's a 289...
Check the crank numbers too. Ford went to the 4 bolt damper in the 70 model year. 3 bolt damper can be either a 289 or a 302.
Pull it apart and check. It could be (gasp!), a 302 block with 289 crank, rods, and pistons. I wonder, if it is, would it be better than a 289 block with 302 crank, rods, and pistons?
Actually in 1968 when Ford was making the transition from 289s to 302s you didn't know what combination of parts you were gonna get. Blocks could be either and rotating assemblies could be either depending on when the different factories ran out of old parts and started using new.
Correction: Block is a D10E, not D5 as previously stated. Rods are also D10E. Only number I found on crank was on rear counterweight, either an 3 or an 8, hard to tell. I'm thinking now, 302, with an early 3 bolt crank, what do ya'll think?
