Re: Gibson Les Paul And Metal Pickup ?
Lowering the pickup is worth a try. Distortion shouldn't be lacking in thump, though. It's not the bassiest ceramic, but it's very popular for thrash.
If you need more low end growl, you might look at the PATB-2 Parallel Axis Distortion, or the Invader if you are happy with all out bass thump but less strong lead tones.
Alt 8 should work too, but I don't have much experience with it and haven't been wowed by the samples I've heard. [They have a funny mid notch, but many say they don't get that, I've speculated it's tied to it being too close to the strings based on reported pickup heights, but am not sure that's been proven yet.]
Recent non-Historic Les Pauls probably want a TB spaced bridge, not SH, by the way. Can make a bit of difference on tone for one or both E strings.
The Custom is a great all around pickup, especially in a not too bright Les Paul. I like the Custom 8 even better, gets this 'vintage metal that never was' sort of tone, modern yet heavy retro leanings. Really cool vibe, and gives you stronger cleans and low gain tones. Plenty of low mid growl and bass, though maybe not quite as tight an attack as the ceramic TB-5 (or SH-5, if your guitar's spacing is narrower).