I've seen some that have never had a wrench on them. I think there's a certain range of heads (like 02-03) where the aluminum alloy used in the heads wasn't just *quite* right; especially for the TTY bolts.

Also, unless an insert was previously installed, replacing the bolts is wasting the customer's money. It's the head that yields, not the grade 8 or 10 steel bolts.

Rhett Yurgin
Technician
Yeargan's Automotive
Carrboro, North Carolina, USA