56 - 59 engine & piston differences ?

[M. Bankes]

Hi,
I am re-building a '59 Caddy motor and want to know what the difference is between 56 - 58, 365 CID pistons, and 1959 390 pistons ? Are the pistons the same ? rods ? Anyone know just what the difference is between the 365 & 390 motors ?
Thanks
Michael

[Dave Shepherd]

Bore sizes were the same, 56-57 pistons are the same, 58-62 are the same, according to Egge's catalogue.  The stroke was changed as the cubes went up in those years, so the rods and crank would be different as the cubes increased.

[M. Bankes]

Thanks, that's what I came up with too.
Anyone know if the '59 heads are prone to cracking, like the '56's were ?

[The Tassie Devil(le)]

Don't forget as strokes change, so does the height of the Gudgeon Pin in the piston.

Not much in life is ever simple.

Bruce.

[imf222]

59 heads Are not prone to cracking

I have 18 heads from seized engines They  are all ok

[curly]

The right (passenger) head on my 59 390 cracked externally between cylinders 2 and 4.  We tried a repair, it didn't take.  YMMV.

T Lewis