bluecab

For the 425 in my Toronado; limited to factory intake and exhaust manifolds.
Opinions? Experiences to relate?
Thanks

cutlassefi

Don't need them, don't use them.

joe_padavano

X2. The oiling system of the Olds motor feeds the lifters FIRST, then the mains and finally the cam bearings. The common restrictors that go in the passages between the mains and the cam bearings DO NOT restrict oil to the rockers. Now, installing the 16 individual restrictors in the holes that feed each lifter WILL restrict oil to the rockers, but as Mark correctly noted, your stock or near-stock engine doesn't need them.