Keep in mind that self modifications to a SFI bellhousing will void the SFI certification, per NHRA. That includes minor “trimming”. Technically you are supposed to send it back to the manufacturer for any modifications. For the little bit you’re talking about no tech inspector will probably notice, and even a lot of “picky” tech inspectors might notice and not say anything, but I’m just giving you a heads up. Do lots of racers do something similar?, sure. Will that little trim weaken the bellhousing?, probably not. But it’s an expensive part, I’m just giving you a heads up first before you touch it. You may also want to consider if you ever plan to send it back to the manufacturer in the future to be re-certified, some manufacturers are picky about re-certifying a modified part. I’m not a tech inspector, but I know NHRA has covered this in the National Dragster in the past. There are authorized companies that modify bellhousings for removable clutch adjustment covers, you may want to ask them, or the QuickTime tech dept. Again, before anyone flames me, am I possibly being overly alarmist?, sure, but a lot of people that don’t race a lot don’t realize this, it’s just something to consider before you start to trim.