Love Lawrence A-300 but have concerns.

[romancandle]

I bought a Fishman Rare Earth Humbucking pickup a couple months back and it must of been a dud because it had really low output. I went back to a Lawrence A-300 and got the tone I wanted instantly. It was rather difficult to install on my Guild M-20 (Reissue). I have used this pickup before on inexpensive guitars but on something like my Guild I'm having second thoughts. Do you think this pickup could cause damage on this guitar? My main concern is how tight it appeared to be in the sound hole. I originally got this for my Seagull S6 Original. Should I just stick with using this pickup on my Seagull and find something else for my Guild M-20? I would be shattered if I damaged my Guild. Any reports on this pickup actually cracking a guitar?

[romancandle]

My Guild M-20's soundhole is 3 1/2 inches in diameter but it just looked too tight. I tried with my Martin Dreadnaut Junior and it fit perfectly. The 1/2 inch difference really made the difference. I compared the A-300 to the onboard Fishman and it was a no brainer for me I liked the sound of the Lawrence much more.

[TNO]

You can bend the metal spring if it's too tight.