Titanium Bolt SPPHH312-24-1500 7M Billet Specialties overflow tanks are

Billet Specialties overflow tanks are machined from 6061-T6 billet aluminum and include an adjustable billet mounting bracket with hidden hardware

They are made with heavy duty roller bearings that keep the leaf spring and the body from binding up during suspension movement

In 1987 GM equipped the Chevy Small Block V8 with roller lifters / provisions for roller lifters

it’s been one of three options

Titanium Bolt SPPHH312-24-1500 7M Billet Specialties overflow tanks areTitanium Bolt5 16 24 x 1 1 2", Hex Head, Wing Pinch Bolt SPPHH312 24 1500 PHH312 24 1500 5 16 24 x 1 1 2 hex head bolt with 7 8" thread grade 5 titanium head size uses 1 2" wrench.