Re: Looking for used engine or long block
1981-1984 Malibu, ElCamino, MonteCarlo with 'K' as the 5th vin letter. Also some Camaros and Checker cabs had that motor. No trucks used it.
The 'K' is important because those cars also came with the GM 231 3.8 V6
Several parts places and rebuilders stock that 229. Swap the cam to your marine one or use Edelbrock EDL2112 cam. Replace the tin core plugs with brass.
If the exhaust manifolds are done too, you'll need OSCO center riser conversion. No other currently manufactured manifolds will provide needed clearance for your selectrim engine mounts. Budget about $1350 for the conversion.
