[Jac Mac]

Try your local hardware shops for a product called 'Nordlock', two piece 'ramped' & 'serrated' washer, only good for RH threads, works great on headers, manifolds, bell housings. Needs a couple of rechecks when used in alloy applications as serrations tend to 'bite' into the softer alloy.... might be just what you need on those 'FE' intakes to keep the bolt clamp pressure up.