Many recommend "extreme" rate of lift cams, with dual valve spring (not drop-in) required to handle the lift (above .500"), when all the owner wants is a healthy sound and more rpm/power than stock. Recently we did a revamp of an old low compression '72 340 build that had a generic 280/.480" hydraulic and we used a Crane Energizer 272/.454" (also Summit has it cheaper in their white box grind) and got a ton more bottom end. The customer never races it and wanted better manners. On a high-comp '69 you could use a Crower "Hot Street Beast" or Eglin "ProStock" 232/242*@.050" .450/.476" cam, similar to this Lunati "Factory Performance" 340 cam (bigger than stock):
This won't be noisy or fussy and will rev to a true 6500+ with fresh stock 340 red valve springs or Comp #901-16 etc. single springs (drop-in). Stock rockers everything. You'll need that 3000 stall converter (NOT what a stock 340 had, 2400) and hopefully 3.55+ gears. Enjoy!!