I too have one of these...
An '83 Malibu wagon, I put in a 350 4 bolt main and a 700r4 tranny out of a wrecked motorhome.
Other than the motor& trans it is completly stock.
This car is a total Sleeper, it is VERY fast but looks like your uncle Fred'* car LOL
My plans for it include a white paint job and a mid 80'* Monte Carlo front nose.
It should be a bolt on swap, I've seen them on 80'* El Camino'* but never on a Malibu Wagon.
Then I want to upgrade the brakes and suspension to match the capabilities of the engine. I also want to put on 80'* IROC/Z28 wheels.
Should be a nice cruiser when I'm done. CD