My fault. Yes. I mean the OEM transmission. The size difference I am reffering to is the distance from head to head. It appeared to me that the 302 that I removed from my truck was wider than the alleged 302 that I bought. Upon further research I do notice a substantial difference in height, which makes sense given the information I was given by my father that the only difference in "size" is that the 302 has a longer stroke than a 289. I am unclear on the exact year of the 289. The number on it is hard to make out due to the age. My main concerns with the 289 set up is the differences in the transmissions. Specifically the shifter position and function and the cooling line connectors.