how much trouble and what kind?

heads or tails ? A new stock oil pump might protest or even etend the life of the new cam. It could wash the main bearing out too.
I would drop the pan and clean the pickup screen. Fresh oil and filter. Happy moparing for who knows how long. i have a 73 318 with 308 K miles. 2nd timing set put in at 26? K miles. Good luck with it.