Clutch Adjustment?

OK heres what I got 68 Dart 383,4 speed,new flywheel,new Hayes clutch, used Lakewood belhousing,and I converted it over to hydralic.
My problem motor is pretty fresh I got around 400 miles on it.Have been driving it easy no problems with the clutch.Today I got on it a bit from first to second.Shifted at 4000 and tranny made I guess a pop sound and is slipping.So I guess the clutch needs adjusted.
My question what is the best way to adjust it? With the Lakewood bellhousing you can't see nothing,no inspection cover at the bottom.So I just kind of guessed at it last time.
My second question is how good do Hayes clutches hold up.Once the engine is broke in I will be shifting it at 6500-6800 Rpm.
Thanks,Jim