[vectorit]

Personally I prefer to hear the seller say to me that it is the original motor from the factory, and I have gone through great lengths on my burb to keep the original running gear. Not that I plan to sell it or anything, it's just me being anal about having an original 1968 K20 burb.

If you want to go BBC instead of the original SBC, then more power to you. It is after all your truck, and you can do anything you want to it.

I had a 68 elCamino with a 327, the original died and I didn't have the resources to rebuild it. I stuck in another better motor, and when I sold it I wanted to keep the engine in it. The buyer was relieved that I kept the original engine, to which I sold with the car and he planned to rebuild it.

If you have the money and resources to go BBC, then go for it since there is plenty of room in the bay for a rat. But I'd keep the original mill tucked away.