727s

[Lee A]

Hi how do you tell the difference between a big block 727 and a small block 727 and also can you put a small block behind a 440 and have a good long run with it for just normal driving

[John_Kunkel]

The BB and SB have entirely different bellhousing bolt patterns so they won't interchange.

The easiest way to differentiate between them is to look at the four bolt holes at the bottom of the bellhousing, the BB has four equal sized bolt holes while the SB has two small holes near the center with two large holes next to them.

[Lee A]

How can you tell from the side if its already in the car

[John_Kunkel]

If it's still in the car with the engine attached, a BB has the distributor in the front and the SB has it in the rear.

[Chryco Psycho]

the 727 is identical internally for both small & big blocks , only the case changes
small blocks also had the 904/999 trans with a square trans pan ,the 727 has a bulge out in the front corner of the pan