I have a beautiful 1957 Pontiac Pathfinder Deluxe sedan that i have restored original. The car has a 261 inline but i am not so sure that this is the original 261. I know this is a 261 because of the steam holes in the head and block. This motor has bosses in the sides for side motor mounts. Because of this i suspect that this motor is 1958 onward because of the required side mounts on those years. Does anyone out there know the correct casting engine numbers for the 1957 261 in line six. Any help is greatly appreciated. George.
__________________
1957 Pontiac Pathfinder Deluxe sedan restored 261 six
1974 Chevrolet Caprice Estate wagon low mileage original 400 V-8
Check the engine number on the passenger side of the block. Then check your data plates the engine number should be the same. I think your engine is a 58 or newer by your description of the side mounts.
That is a real interesting thought. I wonder if that could be possible. Thanks 427 Carl for sparking that possibility. Is there anyone out there that knows that this is possible. That maybe if my car is a very late build that they might have put in a early 1958 261 with side mount bosses in the block. as those engines were available. George.
__________________
1957 Pontiac Pathfinder Deluxe sedan restored 261 six
1974 Chevrolet Caprice Estate wagon low mileage original 400 V-8
I have an update. I now know that my 57 261 is of a 1960 261 vintage. The good folks at GM Vintage services made that clear from my engine number. Also my car was a late build with the date of July 9, 1957. Its too bad that it is not the original motor, but it is still a great engine and i have no intention of replacing it. 261 six in liners forever. George.
__________________
1957 Pontiac Pathfinder Deluxe sedan restored 261 six
1974 Chevrolet Caprice Estate wagon low mileage original 400 V-8
