Alexander Wesley Asks… What's Available for Swapping a 5.7L Gen III Chrysler Hemi into a 1984 Chrysler M-Body?

What’s Available for Swapping

- Marlan Davis

Q: I keep hearing about putting a 5.7L Gen III Hemi into a K-body, but what about an M-body? Is there no info on that? I would like to find the difficulties of putting one of these engines in a 1984 Chrysler Fifth Avenue that has a 318 “LA” small-block in it now.

Alexander Wesley Via email

A: The K-platform refers to Chrysler’s FWD (front-wheel-drive) econoboxes with transverse engines and transaxles made from 1981 through 1989. Converting a K-car to a V8 (any V8, not just a Hemi) requires replacing the complete drivetrain with a longitudinally-mounted engine, conventional transmission, and separate RWD (rear-wheel-drive) rearend. Basically, keep the body shell and ax most everything else. The result is a drag car, or what some call a Pro Street-style muscle car. Not an easy job for the newbie hot rodder!

Your M-body is a midsize, RWD chassis that first appeared in 1977. The 1982–1989 Chrysler Fifth Avenue is one member of this long-lived family, which is also closely related to 1973-and later Chrysler A, B, C, F, and J-bodies in terms of engine drivetrain layout. Stock engine choices for the 1984 Fifth Avenue were either the 225 Slant Six or 318 V8, both shifted by an automatic trans. Most came with a 900-series (A904/998/999) TorqueFlite and 7¼ rearend. Some police cars and taxis stepped up to the A727 Torque- Flite and 8¼ rearend.