The KL1450 loaders came with very weak roll back power. I've complained about that in the past.The hydraulics are much weaker than they should be. I know the front loader on these machines are a joke to begin with...
You could try going with just the larger cylinders first to see if you feel you need to relocate the bucket mounting holes.I'd love more info on how you did your upgrades. Doing a cylinder swap doesn't sound too hard but relocating the mounting holes seems a bit more difficult.