Butler 3/8" Pipe Plug, Passenger Side Oil Galley, Drilled PIO-PP475

SKU: PIO-PP475

Passenger side rear oil galley, recessed inside the block behind the distributor — 3/8" NPT plug drilled .040" to oil the distributor gear. Sits hidden beneath the 15/16" outer plug. Threaded, not press-in. One per engine.

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Pricing: $5.95

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Description

Drilled Oil Galley Plug Pontiac V8 · rear of block, passenger side, behind the distributor

PP475

Specifications

Thread	3/8″ NPT tapered pipe thread — threaded, not press-in
Orifice	.040″
Material	Steel
Quantity	One (1) per engine
Tools	BPI-1030 Butler Pipe Plug Tool, or BPI-Oil-Galley-Plug-Socket (3/8″ drive, 5/16″)

Which Hole Gets Which Plug

Rear galley, behind the distributor	PP475 — drilled, .040″ orifice. Always this one.
Every other 3/8″ galley hole	PP554 — solid, no orifice.

The two plugs look nearly identical in the hand. A solid plug behind the distributor removes an oil feed the engine is designed around. A drilled plug anywhere else bleeds pressure that should be going elsewhere. Count them before assembly: one drilled, the rest solid.

Why It Matters

No oil pressure on first start. A missing oil galley plug is the most common cause. Confirm every plug is in before priming.

Passenger-side lifter clatter. A missing or improperly installed plug on this galley is a known cause of lifter noise on that bank.

Installation

Install before the engine goes in the car. Access behind the distributor is extremely limited once it is in.

Confirm the galley is cleaned through and clear of debris and cleaning residue.
Check that the .040″ orifice is open and clear.
Check the block threads — clean and undamaged. Chase if needed, then clean out the debris.
Start the plug by hand, square to the threads. Never start a tapered pipe plug with a tool — cross-threading the block here is an expensive repair.
Tighten with BPI-1030 or the 5/16″ socket until firmly seated in the taper.
Verify every other galley plug is installed, then prime and confirm oil pressure before first start.

Notes

No torque spec. A tapered pipe thread seals on the taper and is tightened by feel. Do not overtighten — driven too far, it strains the surrounding casting.
Do not drill a solid plug to make a drilled one. Order the correct part.
An improperly seated plug can back out under high oil pressure and dump oil internally. Verify seating rather than assuming it.
The internal drive is shallow and rounds out easily — use the correct tool. Recovering a rounded plug behind the distributor is a bad afternoon.

Butler Performance · 2786 Hwy 43 North, Lawrenceburg, TN · 866-762-7527 · butlerperformance.com

Optional block plug install tube has the square drive on one end and hex drive for 3/8 hex plugs on the other. Turn with a 3/8 wrench to tighten

Butler Tech Library

Every Plug in a Pontiac Block

Size, location and part number for every plug position on a factory iron block — including the hidden drilled galley plug that causes passenger-side lifter clatter when a shop leaves it out.

Read the Block Plug Guide ›

Also HelpfulRestricting Oil in Pontiac V-8s ›Block Casting Information ›