Early GTO oil filler caps
 

The Positive Crankcase Ventilation System.

The “California type PCV closed system” option K24/614 was mandatory for the first 3 years (64,65,66) of the GTO if sold “NEW” in the state of California and applied to both Automatic and Manual Shift cars.

The other 49 states did not require this #614 option on a New Pontiac, therefore making this a rather rare feature to find on a 4BBL. or Tri-Power.

In ‘64 the RH valve cover had a 2-3/4’’ high round stack to accommodate two different push on oil fill caps.
The “Sealed” AC-OIL FC-45 cap for the #614 option looked like a top hat.

The LH valve cover was flat with a rubber grommet to accommodate a black painted steel pipe which lead to the air cleaners.

The last photo shows a ‘64 GTO I owned about 40 years ago that the Original owner I bought it from changed the engine color.

The Standard PCV System for ‘64
 

This more common PCV system had an “Open” push on oil fill cap.

This style cap (FB-39) was larger with trapezoid openings on the bottom and was not crimped around the lip like the following years.

Both ‘64 oil caps are very unique.

The opposite valve cover used a rubber plug to seal the hole.

1965 GTO Oil Caps
 

For Automatic and Manual Transmission.

In 1965 there was another style “Sealed” cap for the California application used on the RH valve cover.
This VC was now flat and used a twist in style AC cap.

This cap was used in 1965 and ‘67 through ‘69, but not 1966.

It is identified with three small spot welds with the AC in the middle.

The LH valve cover was the same as 1964 utilizing the steel vent pipe.

‘65 “OPEN” Cap
 

Standard PCV for 1965.

This cap was also a twist in cap with round holes in the bottom and a crimped outer lip.

Like the ‘64 Standard PCV, the LH valve cover used a rubber plug to seal the hole.

Great info,thanks for sharing!

'

Ditto, great details too and thanks for taking the time.
:beers:
~ Pete

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Great stuff, Chris. As always, thank you for sharing your knowledge!

1966 Option #614
 

Things changed in 1966 in regard to the use of the K24/614 PCV.

If a ‘66 GTO was sold “New” in the state of California it would now have the A.I.R (Smog with air pump) on all models EXCEPT “Automatic with Tri-Power”.

1966 Engine codes with A.I.R. code #616 shown below.

WV - 4 Spd. / Tri-Power.
WW - 4 Spd. / 4BBL.
XE - Automatic / 4BBL.

The YR code Automatic / Tri-Power did Not require A.I.R. but instead was the last model to only have the #614 if sold New in California.

The ‘66 YR #614 utilized a molded rubber hose from the center carburetor over to a nipple on the chrome twist “sealed” oil fill cap.
The opposite RH valve cover was now solid (no holes or plugs).

The 1966 GTO with engine code YR had a build of 1759 total.
There is no record showing the total of the California YR with the #614 option, but it should be substantially less.

The ‘66 Car Billing History Card, as well as the Window Sticker shows #614 for this sold New in California YR GTO.

Chart showing Engine/Transmission with codes and total builds for 1966.

1966 A.I.R. (Smog), code #616
 

1966 was the first year of the “Smog” unit on a car sold New in the state of California.

Option #616 (A.I.R.) is the #614 and #612 combined.
There were three model GTO’s built with the #616 option.
WV, WW, XE.

614 = Special PCV with sealed oil cap and hoses going to the base of the air cleaner.

612 = Air Injection Exhaust Control.

The two color photos show a complete working unit (WV = Tri-Power / 4 Spd.) of which 1550 were produced.
This rare GTO once belonged to my friend Grant Baber.

The black and white photo is a magazine test car “WV” with 3x2’s and #616 option.

The last photo shows another ‘66 GTO test car with a 4BBL. and #616 option.

A few ‘66 Car Billing History cards show the #616 box pertaining to the “WV” engine code.

1967 gto a.i.r.
 

In ‘67 the #616 option became more efficient.

For the #614 portion some changes were made from the previous years.

1) A larger air cleaner base with a different style snorkel and a redesigned chrome lid.

2) The flat sealed AC twist oil cap that was first used in ‘65 on the RH VC is now being used again on the ‘67 on the opposite (LH) valve cover.

3) Likewise the metal pipe from air cleaner to the valve cover is opposite from ‘65.

The #612 portion was also redesigned with different check valves and piping to cylinder head brackets.

Photos, courtesy of Grant Baber of his 1967 GTO Survivor.

The Billing History Card of Grant’s car shows the Fremont build “Z” code.
Engine WW (2006 built).
The #616 option.