The builder does not show which items it needs to build the structure but instead just uses any materials you put in. Could you possibly check why its not using the correct materials in the correct places or why it doesn't even show which material it needs..

I'm running Bevo Tech Pack with the latest buildcraft version.

Could you please open a thread on http://mod-buildcraft.com/forums/index.php?board=2.0 ? That's definitely unknown and require investigation. We're using github only for bugs that are understood and assigned to someone. Thanks!

Are you sure you used a blueprint and not a template?