The complete 142-177 supercharger systems (Chevrolet/Mopar) I have purchased so far never had a pressure relief of any type.
Probably because of the low boost output of these small superchargers?!?

I have a few small block set-ups and a Dick Landy Industries 174 supercharger set-up for a 440.
Here is my DLi intake manifold:








This is an NOS (in box) B&M small block Mopar intake manifold we paid $350.00 for:




1969 Dodge Super Bee A12 (440 Six Pack, 4-speed, Dana 60 4.10)

1972 Plymouth Road Runner (400, 4-speed, 8.75" 3.23)

1974 Plymouth Duster 360 (360, 4-speed, 8.75" 3.23)