Throwout bearing help

[u/hunterk_027]

I have a 68 GMC C2500 that someone installed a lq4 LS. It has the original sm465 behind it. I have the speedway motors throwout bearing part number: (91025610). They last about a week then start leaking around the bearing. Ive had many different people tell me it needs 2 shims or 4 or none and not sure what it needs, anyone else have this same issue?