OK, so I'm sitting there reading my Car Craft mag and BANG! it hits me right between the eyes
A) the 151 has the same cylinder spacing as the SBC (4.4") with a four bolt per cylinder head bolt pattern.
B) the LS series of engines has the same cylinder spacing as the SBC (4.4") with a four bolt per cylinder head bolt pattern.
So, the question now is " how close are the cylinder head bolt patterns between the 151 and the LS engines?"
Any LS head would really wake up a 151 if it could be made to fit.
Other possible problems (other than bolt pattern) would be the cam (different sequence of intake and exhaust lobes/valves) and a coolant outlet and thermostat.
If someone else has already mentioned this, break the news to me gently.
Ken
My other car is a Nova.