Swap Desoto Straight 6 into 55 Pickup?

[Me56Dodge]

This is my situation.

My 55 Dodge Pickup is titled as a 56, however it came with a 270 poly and 3 speed on the floor transmission. The 270 poly has a cracked crankshaft, and the cost to rebuild it is beyond my finances.

I can pick up a rebuilt Desoto Straight 6 for only $200, I have read that the Chrysler and Desoto straight 6 had a 25" block, more beef between cylinders, and harder crankshafts.

I know from a few bad experiences that the Dodge straight 6 crankshafts were known to crack as were the Plymouth straight 6 230.

 

Does anyone know if the Bell Housing from a 230 Straight 6 Dodge truck motor (which I already have) will fit on a Desoto Straight 6 Flat Head with a 25" Block?

I know that the block length of the Dodge straight 6 is 23" and the Desoto is 25". I've read that if the Radiator is moved front of the radiator bracket if extra room is needed.

 

The first 3 pics are of the Desoto Motor, the last 2 are of the 3spd. Dodge Trans I have.

 

Can Anyone Please help me??

 

THANKS!

Edited December 30, 2020 by Me56Dodge
add Pics

[55 Fargo]

Okay a couple of things.

Yes the 25 inch engine will fit, your front engine mount will need to move forward. The rad will need to move forward too, not a big deal.

That bell is it from a C series truck?

The B series bell is different, oh it will bolt up but it has the MC attached to it. The C series truck bell has no such provision for the MC to attach.

The Desoto engine, plus a c series 6 cylinder bell and 8 bolt flywheel and your in business. But you will have the 251 engine moved 2 inches ahead of what the 230 would be. Your 3 spd trans in truck should bolt to correct C series bell too.

Keep us posted.

Edited December 30, 2020 by 55 Fargo

[Me56Dodge]

THANKS SOOO MUCH!

 

I was told by the guy I bought the bad 230 engine and transmission from that it was from a C series. How can I tell? 

Or would you have the part numbers I can look for?

I apologize for my ignorance...

 

Patrick

Edited December 31, 2020 by Me56Dodge
new info

[55 Fargo]

2 hours ago, Me56Dodge said:

THANKS SOOO MUCH!

 

I was told by the guy I bought the bad 230 engine and transmission from that it was from a C series. How can I tell? 

Or would you have the part numbers I can look for?

I apologize for my ignorance...

 

Patrick

The C series bell will not have a bracket on side for the master cylinder. Your 270 Poly bell should be similar..

[Me56Dodge]

Thank You!

Is there a place for me to decode the casting number of the Desoto engine?

 

[JBNeal]

additional information - Flathead Identification 

[Frank Gooz]

Good Moring,

I just bought a tranny adapter to put a late model tranny behind a 251.

I called back as the part number is called a 230/350.

The owner told me he has not seen a Mopar flat head six that is different that his plate will not fit yet.

So I would say that it will bolt up. but other things may not be there like bot holes and threaded hole.

[55 Fargo]

2 hours ago, Frank Gooz said:

Good Moring,

I just bought a tranny adapter to put a late model tranny behind a 251.

I called back as the part number is called a 230/350.

The owner told me he has not seen a Mopar flat head six that is different that his plate will not fit yet.

So I would say that it will bolt up. but other things may not be there like bot holes and threaded hole.

Well great 4 it...lol Yes the pattern on rear of the 23.5 engine and 25 inch engines is same. Crank depths and bolt patterns may vary. Meaning a 201 or 217 has a 4 bolt crank while a 230 has the 8 bolt crank.

What is the trans adapter for?

The T5 on the truck bells does not require an adapter plate. It requires a center hole retainer and a pilot bearing, throw out bearing bushing, clutch disc change etc.

The A833 swsp requires an adapter plate for both car and truck application's.

Edited December 31, 2020 by 55 Fargo

[Me56Dodge]

1/2/2021 UPDATE!

 

Through the registry, I found out that my truck is a C-3-C8. It was titled as a 1956, but manufactured in 1955 in Detroit Michigan with a build number of 1249. Back then in Pa. a Left Over Truck from the Previous year was commonly Titled as the year that it was sold in. HARRISBURG is SUCH A HOT MESS! 

 

I found out the the Desoto Engine is a 1949 Desoto S13 237 Cubic Inch. Block Casting number is 1128129-1, Head Casting is 1313825-2,

and Engine Block # Is

49 

2-61

Sl3-b 6883

 

Does this new information change anything about the advice  "

Yes the 25 inch engine will fit, your front engine mount will need to move forward. The rad will need to move forward too, not a big deal.

That bell is it from a C series truck?

The B series bell is different, oh it will bolt up but it has the MC attached to it. The C series truck bell has no such provision for the MC to attach.

The Desoto engine, plus a c series 6 cylinder bell and 8 bolt flywheel and your in business. But you will have the 251 engine moved 2 inches ahead of what the 230 would be. Your 3 spd trans in truck should bolt to correct C series bell too."

 

Thanks SOO MUCH ! HAPPY NEW YEAR!!!!

Patrick

 

[55 Fargo]

55 minutes ago, Me56Dodge said:

1/2/2021 UPDATE!

 

Through the registry, I found out that my truck is a C-3-C8. It was titled as a 1956, but manufactured in 1955 in Detroit Michigan with a build number of 1249. Back then in Pa. a Left Over Truck from the Previous year was commonly Titled as the year that it was sold in. HARRISBURG is SUCH A HOT MESS! 

 

I found out the the Desoto Engine is a 1949 Desoto S13 237 Cubic Inch. Block Casting number is 1128129-1, Head Casting is 1313825-2,

and Engine Block # Is

49 

2-61

Sl3-b 6883

 

Does this new information change anything about the advice  "

Yes the 25 inch engine will fit, your front engine mount will need to move forward. The rad will need to move forward too, not a big deal.

That bell is it from a C series truck?

The B series bell is different, oh it will bolt up but it has the MC attached to it. The C series truck bell has no such provision for the MC to attach.

The Desoto engine, plus a c series 6 cylinder bell and 8 bolt flywheel and your in business. But you will have the 251 engine moved 2 inches ahead of what the 230 would be. Your 3 spd trans in truck should bolt to correct C series bell too."

 

Thanks SOO MUCH ! HAPPY NEW YEAR!!!!

Patrick

 

Nope it does not. The 237 is no different than a 251.

[Me56Dodge]

AWESOME! THANKS SOO MUCH. I've READ THAT THE 237 Desoto engine is Very Good. Can't Wait to get it installed and have Myrtle Back on the Roads after a 40 year nap.