by Bob Doty

K-Members and engine swaps

This is a popular area for discussion. Many [San Antonio Mopar Club] members want to make engine changes from one family to another. Example: swap from an A engine to a B or RB or switch from a slant six to a V-8. There are three basic questions to be asked. Did your desired combination ever exist? what body will be used? and will a K-member change be required?

Everyone who hasn't done it, thinks that a K-member swap looks intimidating It is really very simple and easy to do. There are some easy swaps that require no K-member change.

A-body 1964 through 1966

The V-8 used the same K member as the slant six. Use the brackets and insulators from a 273 and bolt in a 273, or 318. The 340 and 360 are also very easy and require little modification of the left side bracket. Stay away from big blocks in this body. The engine compartment is too small and one problem leads to another.

Big blocks can be installed in the later A-bodies by using the 383 K-member, brackets and insulators. The 440 will fit on the same K-member.

B-bodies 62-72

There are three basic combinations with this body style. The slant six, the V-8, and the Hemi. This makes engine swaps very easy, if you have a V-8 K-member. Simply locate the correct brackets and insulators and bolt them in. Six cylinder conversions will require the change to the V-8 K-member. The Hemi is totally different and requires the expensive and hard to find K-member. Example: a '66 Charger with a 318 can become a 383 or 440 car with relative ease.


The E-body is the easiest to swap engines in, due to the fact that it was produced for five years and every V-8 except the 273 was offered. Only the Hemi requires special pieces. Locate the correct brackets and insulators and bolt it up. Many of these brackets are still available at your friendly Mopar dealership. The 318 uses certain pieces, the 340 and 360 use the same pieces, and the 383, 400, and 440 use the same pieces. All V-8 K-members were the same, except for the Hemi.


When I refer to the brackets and insulators I am referring to the steel piece that bolts to the engine, and the rubber motor mount.

A helpful tip for engine swappers: Imagine a manual transmission with a bell housing; now imagine a 904 or 727 sitting by itself. The distance on all transmissions from the crossmember mount to the front of the bellhousing or case is exactly 22.66 inches. This is the dimension on all transmissions. Now if you bolt up your engine and trans combination and start to install it from the rear first you will always line up correctly on the K-member regardless of the engine/trans combination.

....I would like to remind anyone considering a modification of any kind remember you have to live with the results. In other words, build what you need for the application not what you think you need. There is nothing more disheartening than too much camshaft, not enough converter, no vacuum, too much gear to make the cruises, overheating, and miserable driving tendencies.


Bob Doty

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