I'm pulling the original 350 out of my 69 Malibu this weekend and wanted some opinions on how I should proceed. Should I use the original engine as a foundation for building a higher HP motor or should I sell the engine and put that money towards a new one? Power wise I'm looking for 350-390 HP. The casting number on the heads is 3932441 if that makes any difference. Thanks in advance for any feedback. I'm new to this and want to make the right decision.