Farley`s Dodge Diplomat Forum

Forum Index => The Library => Topic started by: Reggie on January 12, 2008, 00:09:15

Title: Engines: Swaps: Big Block Swap
Post by: Reggie on January 12, 2008, 00:09:15
Big Block M-Body Swap

For cheap, durable, stump-pulling, ground pounding brute power, a Chrysler big block engine combination is hard to beat. Introduced in 1958 with modest 350ci and 361ci displacements, Chrysler's bulletproof big block design has proven its worth through the years. Along the way, Chrysler big blocks grew in size to the pinnacle factory 440ci displacement, and earned a well deserved reputation for delivering awesome power with simple modifications. 

Types of Chrysler Big Blocks

Chrysler big block engines came in two basic types:

"B" and "RB" heads will interchange between block types, but the intakes will not due to the greater distance between the heads on the taller RB blocks. Most other components will interchange except for the cranks, which have different journal sizes.

Although M-bodies never received big block engines from the factory, there has been considerable interest among M-body owners in swapping in a big block. Indeed, several of Farley's Forum members have done just that.

Case for the Big Block Swap

Below, excerpted from several posts by Farley's members, is what is needed to swap a big block into an M-body. Note that this swap requires considerable planning, knowledge of parts interchangeability, junkyard scrounging and possibly fabrication skills.  It is NOT for the faint of heart, but it is a very worthwhile and rewarding swap if you want all out raw blistering power with longevity and without a lot of radical engine modifications. This page is a work in progress, so please let us know if you have any updates or corrections. 

What You Will Need:

Front End Weight Considerations:

Mileage Considerations:

A Few Big Block Diplomat Specs:


Title: Engines: Swaps: Big Block Swap - Page 2
Post by: Reggie on May 08, 2008, 21:00:20
Big Block M-Body Swap - Page 2

Below are additional notes from member S-type (https://www.dippy.org/forum2/index.php?action=pm;sa=send;u=10) on K-member considerations regarding this swap:

"Two places you may encounter interference when you do the big block is at the rear of the K where the oil pan is and where the oil filter is by the steering box mount. It varies from car to car, but you may have some trouble at those two points. Also, you may want to roll the seam on the firewall a little where the bell housing goes. If it rubs, it can be annoying."