Brother in-law is getting an 89 Raider with a 2.6L gas engine, the engine is locked, was spitting oil badly and in general bad shape.. he's not even sure if a rebuild will do.

What are his options for engine replacement? How hard would it be to drop the 3L in? I know they used the 3L in a ton of vehicles and with a few modifications most will fit in the Raider.. but can you swap the 2.6 with the 3.0 without having to do insane modifications?

Same drivetrain? what's different?

He's also considering a Diesel swap, which I know is a bit more difficult.

Thanks for any help you can offer.