"This is as big as it gets - club wise is does not get any bigger than a Heineken Cup final - the magnitude of this game is just massive," said Tuohy.
"Yes, I have played against the big fella before when I made my Ireland debut in New Zealand two years ago. However, we got a drubbing. We were on the end of a bit of a hiding and it was not a great experience.
"He hit me a few times in a few rucks, which left a pretty lasting impression, so hopefully Brad will be the one on the receiving end this time."
Springbok Johann Muller, Ulster's captain, and Tuohy are set to go up against Leinster skipper Leo Cullen and Thorn in the critical line-out aerial battle.
"Leo and Brad have got unbelievable records in the game and while Johann would be considered in the same bracket as those two I guess I am the one who is a bit wet behind the ears internationally," added Tuohy.
"But I hope I can impose myself on the final and make a lasting impression.
"I played at Twickenham for Hartpury College against University of Wales Institute, Cardiff in front of around 3,000 students in the 2006 BUSA final, so the atmosphere will be slightly different on Saturday. We won that final so I am one from one at Twickenham - which is not a bad record."
While Leinster are challenging for an unprecedented three Heineken Cup crowns in four years this is only Ulster's second final appearance.
"We have had to wait 13 years to get into another Heineken Cup final but the atmosphere is fairly relaxed and there is enough experience in the squad to keep the boys' feet firmly on the ground as we have not achieved anything just yet.
"We are in the Heineken Cup Final but that is all we have achieved so far so lets hope we can be Heineken Cup winners and not just Heineken Cup finalists.
"Leinster did the double over us in this season's Pro12 but I don't think that makes them favourites for the final. What does make them favourites is having won two Heineken Cup finals in the last three years and, while we are no illusions that we will be the underdogs, I think that suits us just fine.
"We were the underdogs when we went down to Munster in the quarter-finals and delivered but I think the pressure got to us a bit in the semi-final against Edinburgh at the Aviva and we did not play to our full potential.
"It wasn't until the home Pool game against Leicester that we really put in an 80-minute performance and got people up on their feet realising we are a force to be reckoned with, but that Munster game was the key.
"As we will be the underdogs on Saturday, I think you will see us as a different animal as the pressure is on them as favourites to win the final.
"Both clubs have great travelling support so hopefully it will be 50-50. They certainly had magnificent support out in Bordeaux and we take a lot of support with us so it should be an incredible atmosphere. Hopefully we'll have as many fans there as Leinster."