Proper Oil Cap for a 65 and 66 GT350

[Greg]

I was researching oil caps to see what the proper assembly line oil cap is for a 65 and 66 GT350 and found there are two specific types.  One has the square box FOMOCO and one has the oval box FOMOCO.  I am looking for an original one for a 65 in good condition so which should I be looking for?  Thanks

[Brant]

The oval style in correct for a '65.

[Greg]

The oval style in correct for a '65.

Thanks Brant, is the square style for a 66?

[kingchief]

Oval style with the 2 dimples! 

Cheers,

Steve

[Brant]

The oval style in correct for a '65.

Thanks Brant, is the square style for a 66?

I have seen the oval style throughout '66 production.

[gt350hr]

+1 , the block was '67 and later , + service parts.

[Bob Gaines]

The oval style in correct for a '65.

Thanks Brant, is the square style for a 66?

Here is a over view. As it pertains to Shelby's ,the closed emission cap (one with nipple) with the FOMOCO in script inside a oval was used on 65/66 . For 67 the GT350 emission equipped cars only used the closed emission cap with the FOMOCO in block letters inside the rectangle .  68 GT350 used the closed emission cap with FOMOCO in block letters inside the rectangle.  69/70 GT350 used the same closed emission cap but marked with AUTOLITE.

[6s1640]

There is a nice repop out there with oval Ford script with hose connection, but no dimples.  I believe the dimples are from a spot weld.

It is possible to purchased a NOS black version with correct markings and dimples and then have chromed.  It does require some disassembly and re-crimping the the lower flange.  I think S2MS may have discussed on the prior forum 1.0.  Finding a chrome NOS version is much harder.  There are used versions that do show up on a popular auction site, but you need to be patient.

Cory

[gt350hr]

     +1 Cory.
    To add a bit , the logo stamping rarely goes below the surface unlike the photos above. The spot welds aren't usually as obvious either.
   Randy

[kingchief]

Cory helped me 4 years ago with the black version.  He broke it down and then I sent it off to re-chrome.  Looks very good [see photo].  As he said, very hard to find a NOS or GOOD used one.

Thanks Cory as always.  The only thing was re-crimping the lower flange.  I tried but eventually gave up as you really cannot see it from the top.

Cheers,

Steve

[GT350Lad]

Looks good Steve. I have been looking for a good NOS or used for a few years now with no luck?
Who sells the repo?
Cheers

[Bob Gaines]

Looks good Steve. I have been looking for a good NOS or used for a few years now with no luck?
Who sells the repo?
Cheers

NPD or Virginia classic. Just be sure to pick the one with the correct trademark because there are several choices.

[GT350Lad]

Thanks Bob, I'll have a look

Cheers

[Brant]

There is only one reproduction of the emissions style (push on with nipple for hose as correct for the '65-66 GT350) oil cap available.

The original did not have an ® marking. The reproduction is the same.

The difference in the two is the presence of two spot weld dimples on most originals. Otherwise, the reproduction cap is spot on.

https://www.virginiaclassicmustang.com/CHROME-PUSH-ON-OIL-CAP-WITH-TUBE-AND-FOMOCO-OVAL-STAMPING-P1337.aspx

[GT350Lad]

Thanks Brant