57 De Soto 361-how to tell what it really is?

I was given an engine out of a 57 De Soto Fireflite, which should be a 361. It looks right, like a 383/440, but the motor mounts seem to be fabricated, so I wonder if it's a different year/size. How does one tell on these Mopars? I'm not that familiar with the casting/ID numbers on these engines, so I don't know how to determine what it really is. Thanks, Rob

 

'57 DeSoto Fireflite would have had a 341 Hemi with a 2bbl, and the engine casting (on a flat machined pad under the thermostat) would be S25-XXXX with the X's representing a sequence number.

1958 DeSotos could be had with 350s and 361s, both low-deck "B" big block Mopars - the first year for them. And a 361 would be correct for a Fireflite or Adventurer.


So.. where is the rest of it?

 

Ooooohh.... possibly a really early B/RB... very very cool!!

The easiest way would be to look near the distributor on the front of the engine. If its a B engine there will be a little flat pad very close to the distributor, displacement should be stamped on it. If its a RB engine the flat pad will be on along the front valley pan gasket rail on the driver's side.

Does it have 4 bolt or 6 bolt valve covers? The early engines had 4 bolt valve covers, unless the heads have been changed.

We need pictures!!

 

Thanks for the info. I'll look tonight to see what it really is. The rest of the car became parts for a friends 57-it was rusty but had lots of good pieces on it. It's not a 341 hemi-it looks very similar to the 383-440's I remember except for the Carter 2bbl carb. Rob

 

A friend had a ragtop Desoto Adventurer B-block, with factory 2X4s, but I believe it was a 350. Seems it was a '58