Western, finding a 327 should not be very difficult, but finding a 275 HP will be. It is even hard to find any information on them. It sticks in my mind they were used in the 68/69 era and the large journal blocks and possibly in truck motors. I have gone back thru some of my literature and did not find what I was looking for. The more common models are the 250, 300, 350 and 375 HP models.(if you want to call the 350 and 375 common). The higher HP the more difficult to find)
The early 250 HP had the 4 barrel, but small heads. The 300 had the double hump heads, AFB 4 barrel, and 2.5 inch exhaust manifold dumps. The 350 Hp had the above, but more radical cam and solid lifters. The 375 had 350 stuff with 2 4 barrels. This is quick and dirty, hitting the high spots.
Trees