PRP Double Head Drain Oil & Coolant - Nissan RB20/RB25/RB26This well engineered piece of gear is specifically designed to maximize fluid flow out of the back of the Nissan RB Twin Cam cylinder head where it needs it most. Everyone has seen an aftermarket head drain, but this ticks all the boxes, this new PRP unit allows oil drainage to the left or the right or both, which works well for the dry sump user. More importantly, water flow, a dire must for all race, semi grout and full grout filled block