wellm mine dont have a hole in the top so here is what i did i measures the center between the 2 top bolts on a my big block (in car) it is 8 inches(or close enuff) from center of bolt hole to center of bolt hole and the small block is 6 3/4 some tranny have a inch and a half or so on top but those are for motor homes and vans to check the timing through
ralph


1970 barracuda convert. 1 of 59
1970 pro street A.A.R. clone (panther pink)
1971 charger
2015 hellcat challenger. Redline red
2014 quad cab 4x4 ram 8 speed hemi