Roller Lifters in a 69 340 block

I really have 2 questions:
1. How difficult is it to put a roller lifter cam in a 340 (69 block); and,
2. Is it worth it?
I have a 69 Barracuda with a warmed over 340 pushing about 375 HP. It has Comp XE268 cam, Eddy Air Gap, Eddy 750 Carb, Headers, 4 speed and 3.55 gears. Although I have been VERY pleased with this combination, I was thinking about more power. Would the change to a roller cam be beneficial, or should I just focus on getting my heads ported and maybe go to the XE 272 cam?
PS I did just read the thread called Roller Lifters, but it did not answer my question.