As long as they are fiberglass they will all be a little bit different....reason being #1 air temp #2 human hand lay-up......How fast you lay up, how much resin, air temp.....everything shrinks, pulls, tightens at different rates....on a hot day with a fast cure things get sucked in pretty hard....winter day things might move a lot slower, maybe even still curing after parts come out of the mold...all close but different...da Bat