Reassembling after power coating and noticing the flappers only open manually about half way. Is by by design to provide for some backpressure or should they be fully open (parallel with pipe)? Engines are all stock 1996 7.4 LX MPI's.

I searched videos, pictures, Corsa's website and this forum and the flapper position is not addressed.

Thanks for any help you can lend.

Full open

Thanks, putting them back together after powdercoating the pipes and adjusted accordingly.