58 to 65 fuel injection distributor oil line fitting

[John D.]

I need your help in settling an argument with my pal. If any of you have a bow tie fuel car that has the original distributor oil line fittings on it this is what I would appreciate you checking for me (us).
The "T" fitting thickness. Just so you know which fitting I am referring to I will try and tell you.
First of all you have a coupler fitting that screws into the engine block. Then you have a t fitting that screws into this fitting.
I am saying that original are only 1/2" thick. My friend says they should be 9/16" thick.
Well then if so my repro distributor oil line kits in my catalog have the correct T fitting in that they measure .562 which is 9/16". I just looked on the chart and .5625 is exactly 9/16". Now I have always known my fittings are too fat. Typical stuff from say NAPA. So then how can an original car have a 9/16" thick fitting. My friend who is a frequent contributor to this forum says my LWC has a fake fitting on it. Measures 1/2" thick.
I have several old greasy junker fittings that I thought were original and they measure 1/2".
Your thoughts please. Thanks, JD

[Gary C.]

Re: 58 to 65 fuel injection distributor oil line fitting

John, the thinner fittings are correct than the current replacements we use. Had an original and loaned it out. Don't think it was ever returned, but will check and post the measurements if it was. Have seen one piece pipe "T" with an integrated nipple on '57 original engines as well. Think Ken Kayser has one on one of his early engines. Best, Gary....

[Dan H.]

Re: 58 to 65 fuel injection distributor oil line fitting

John, Gary, I still have my original fitting on my 64 FI, it is 1/2" thick, has the 'male' end that screws into a fitting in the block. OK, who's got the blueprint?
Dan

[Mike M.]

Re: 58 to 65 fuel injection distributor oil line fitting

i have 1/2" thick on my mid year FI's. mike

[John D.]

Re: 58 to 65 fuel injection distributor oil line fitting

John, Gary, I still have my original fitting on my 64 FI, it is 1/2" thick, has the 'male' end that screws into a fitting in the block. OK, who's got the blueprint?
Dan

Good job Dan. You have a winner for sure. We have been trying to get the blueprint of that oil line for an eon. I bet Futo has it. Maybe MH has the print on the fittings.


There is at least one judge that carries a 1/2 wrench with him when he judges fuel cars for this minor detail. Chews tobacco.
Now Dan we need a few others to firm this detail. Not to put a wrench into the 1/2" thing but do you suppose GM had 3 plus suppliers of this fitting and that at least one of them used a thicker one??? I only said this because my friend knows of an original earlier FI Corvette that has a 9/16"thick fitting. Thanks, JD

[John D.]

Re: 58 to 65 fuel injection distributor oil line fitting

i have 1/2" thick on my mid year FI's. mike

Thanks Doc. I was hoping you would check. JD

[John D.]

Re: 58 to 65 fuel injection distributor oil line fitting

Jorjorian and another friend emailed and said their midyears have the 1/2" thick fitting.
So now getting away from the midyears for a bit lets here from some of you solid axle cars with original distr oil line kits on them.
There is a certain 62 FI car out their thought to be all original. It does NOT have a 1/2" thick fitting. There are a ton of you with original 62's and older so please check for us. Thanks, John

[Dan H.]

Re: 58 to 65 fuel injection distributor oil line fitting

Good job Dan. You have a winner for sure. We have been trying to get the blueprint of that oil line for an eon. I bet Futo has it. Maybe MH has the print on the fittings.


There is at least one judge that carries a 1/2 wrench with him when he judges fuel cars for this minor detail. Chews tobacco.
Now Dan we need a few others to firm this detail. Not to put a wrench into the 1/2" thing but do you suppose GM had 3 plus suppliers of this fitting and that at least one of them used a thicker one??? I only said this because my friend knows of an original earlier FI Corvette that has a 9/16"thick fitting. Thanks, JD

John, never say never, but in my box of old FI stuff I have a fitting with circle 'W' on it, male fitting on the bottom as does the 1/2" one on my 64 car, however it is 9/16" vrs 1/2" on my 64, earlier variation?
Dan

[Jerry G.]

Re: 58 to 65 fuel injection distributor oil line fitting

I just checked my 61 315 Fi and it's 9/16. It's been on the car for the 35 years that I've owned it. It looks older than dirt. I think it's original. Jerry

[Bill M.]

Re: 58 to 65 fuel injection distributor oil line fitting

So now getting away from the midyears for a bit lets here from some of you solid axle cars with original distr oil line kits on them.
Thanks, John

My '59 has a 1/2" tee. It is definitely an original FI car, but was wrenched on extensively by a teenager, so I can't be 100% positive it's original. That teenager remembers leaving that fitting out of the block when he re-installed the engine. There was oil all over his parents' garage ceiling and the '59's windshield faster than his hand could get to the key...what a mess!

[John D.]

Re: 58 to 65 fuel injection distributor oil line fitting

I just checked my 61 315 Fi and it's 9/16. It's been on the car for the 35 years that I've owned it. It looks older than dirt. I think it's original. Jerry

Older than dirt is really old Jerry. I have been waiting for this post. Sorta puts a wrench into the theory that the fittings were ALL 1/2".
The word ALL is a dangerous word isn't it.
Need to here from more of you. Thanks Jerry. John

[William C.]

Re: 58 to 65 fuel injection distributor oil line fitting

One on my car is 1/2 inch, can't get to any "spares" at the moment.

[John D.]

Re: 58 to 65 fuel injection distributor oil line fitting

Still waiting for you 58 to 62 FI owners that have an original T fitting for the oil line kit to walk in the garage and see if a 1/2" or 9/16" wrench fits.
I realize though that over the years 1000's of repro oil line kits have been sold. But hopefully some of you have known originals. Thanks again, John