Do i need a stronger clutch or more power?

Im pretty sure the problem isnt the clutch or power, well its more the clutch. You really dont just dump the clutch a 6k RPMs. Rev to like 3k ish and feather the clutch more agressive each run untill you have problems. I think what is happening is your clutch is slipping when you just dump it and at 6k is when it can grab it. It is actually good it slips when your doing that because if you clutch grabs at 6k then it rips up your tranny, if the tranny handles it (Till it implodes) goes down the drive shaft to the rear end gears, Provided you had ZERO wheel hop/traction loss you rear end gears would get ripped appart along with your tranny and your clutch will wear horribly fast. So at least if your clutch cant handle the 6k dump your tranny isnt getting FUBAR along with the rear end gears. All that is provided you have a stock tranny/rear end, if your built for that then get a better clutch.

Just IMHO

the other thing is sometimes if you are bogging it could be because of a too rich condition. what you should try is limiting the traction a little by putting a little more air in the tires then take a pass and keep trying that till you get the 60' you are looking for.

maybe try 18 psi. also remember that if 1 tire is in the sun the heat will make it have more air pressure then the other. so check em before the race.