I think the single ram would be more than adequate. I think there's a video on Hardin Marine's site showing an installation. I believe if the drive is loose and you repair or replace the worn parts your problem will go away too. There are some who say if you're running above 70 mph you should have hydraulic steering. Good luck with your project.

No we don,t have hyd steering but plan to add it in the future as once in a while it will throw the steering belt off when hitting 7000rpm the pulleys are lined up too i think ill try some different brand belts , its not a big issue as its rare to really wind it up that high but it sure is fun!

7000 rpm?

You need to change the pulley size on the crank if you are running 7000 RPM. (smaller)
And also install hydraulic steering.

My Tantrum also will chine walk as it approaches 70 in certain conditions, if in waves hitting from the side or a boat wake. First season I had it scared the crap out of me, as it was my first deep V. Had the gimble replaced as it was pretty worn seemed to help tremendously as it doesn't do it as much. No hydraulic steering yet, 502 mag(stockish) only does 70ish max, but I can trim to the moon with no effects. Hydomotive 25 prop was on it first few seasons with alot of stern lift, then went to a 3 blade mirage that helped alot too, but sucked getting out of the hole. Ended up with a 5 blade that works well, but still would occasionally walk when conditions were right, don't have the balls to "drive thru it", I always back out of the throttle a bit, trim in..then back on it when it settled down. Been a few seasons since I even gotten to play with it, but will get back on it some day!
Good luck with your Tantrum, the more you drive it the better it gets.