I'm running a stock length no-link swing arm on my dune bike. You didn't mention what length of PEP shock you were planning to use out back, but Alkyzilla is correct, use a shock that is designed for a no-link set-up. I was able to closely duplicate the rear geometry of a Polaris Predator 500, which is a no-link bike. I also used a Fox Podium shock from the Predator as well. If I remember correctly, that is a 19" eye to eye shock.