Take all the guess work out of it and do it right once. Another wote for Bob Madara/Marine Kinetics. It's a no-brainer.

How many rpms do you want to spin the engine????

The 731 or 741 will work fine and neither should have reversion issues with the CMI's.

I used a 731 in my 525SC with no problems. It will make good power to at least 5300rpms. That is where I spun mine since I kept the stock rev limiter. The 741 will make a little more power on the top end, but you will need to spin it faster, probably 5600+ rpms.

Contacting Bob M is always good advice and he can custom grind you something possibly better.

yeap..contact Bob...just redid 2 525SC's upgraded to his designed rollers...look no further...

I want to spin the engine at around 5300 rpm like your setup, i will run with the stock 525sc gen 6 rev limiter and ignition for this summer.

I have contact Bob Madara a real pleasure to talk with.

I am wating about is suggestion and kit price.

This is the best move you could have made !!!And yes , for a man with his credentials , he's about as down to earth as they come and will not pump you full of shat . The best thing is , you can trust him to do it rite and to do it the best !!