This may be a silly question but how long has it been since you adjusted the valves? They will loosen up over time.
That said, you're probably aware of the new oil formulations now. The 10W30 you used 10 years ago isn't the same as what you get today, it has much less ZDDP (zinc) in it. A lot of the guys around here are going to Shell Rotella or some other brand of heavy duty diesel oil, but even that has a new formulation you want to stay away from. The "old" CI-4 spec is what you want but Wallyworld doesn't carry it anymore, at least around here.
I use Castrol GTX 20W50, it has one of the highest ZDDP contents of any of the "dino" based oils.
