144 / 170 The same block?

[Nathan289]

all 144/170/200/250 heads will inter change, but there is a difference in intake log volume and combustion chamber (c.c.) volume as well.
There is also a difference in the carb hole size and intake and exhaust valve size.
Cited From the Perfomance six handbook

you can over come the C.C. size by milling the head to regain compression and get the benifit of a larger intake log and bigger valves when using a later head.

I may be installing a 72 250 head on the wagon Dan is selling me, if that is what is needed..

Nathan