[lovehamr]

Just a couple of points:
Any small block with a casting code of C8 or earlier can be a 289 and regardless of whatever else is in the casting # it could be a 302 as well. If you look to a few small block forums you'll see some specific instances.

The dividing year for 289/302 is 1968 and any small block car/truck that year could have either one as production was running through at least 7 assembly plants in the US for that year and they would use what they had on hand.

Aside from the Indy block, no 289s (that I'm aware of) were 4 bolt mains. The 289 HiPo s and the Mexican 302s made do with larger 2 bolt caps. Of the 302s only the tunnel port and Boss engines had 4 bolt mains on #2,3 and 4, #s 1 and 5 were like the HiPo caps.

On crank pullys; the 289s and 302s all the way through most of 1969 had 3 bolt mounting and in 1970 they switched to 4 bolt pullys.

Since I'm on the right coast I no nada about SB100 except that it's some kind of evil Kali thing to make car guys sweat bullets. In reality though any small block casting # of C8 or earlier should be counted as a 289.

Steve