They are not noisy, maybe even a little quieter than stock because they are so thick. They will clear stud girdles, or at least they did the Comp girdles on my brothers truck. To add holes, thats easy too. They have pre-shaped places underneath to locate a 1 1/4" hole saw (the instructions actually TELL you to do it this way) for making holes. Comp also sells some trick polymer breather stands for them also. Our experience with them has been good. We got the red ones. They have little points or "teeth" on the sealing rail to hold the gasket in place. They look really good, and seal very well also.
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82 Z28 383, Ported 215cc Dart Iron Eagle Heads 72 cc Comb. Chambers, Comp custom grind Hyd roller cam, Speed Pro .250" domes, Wheeler Motorsports 4340 I beam rods, Eagle 5140 steel crank, Weiand Team G intake, Holley 830 DP, hedman headers
Trans: Turbo 350 w/ 4000 stall -- Rearend 7.5 w/ Richmond 4.10's, Auburn Minispool
Best ET:11.63 @ 113.25, w/ a 7.39 1/8 @ 93.04, and a 1.626 60'
89 RS, L03 305, Hypertech Chip,cat delete, Dynomax exhaust,K&N open element Filter,160 stat, MSD coil --Trans:700R4 Corvette Servo -- Rearend: 7.5 GM 3.42 w/ posi-lock
New Best ET: 14.91 @92.9
Bassett Racing 
