I’m very surprised your oil stays clear for 2500 miles. Your motor must really be in top condition.
BTW: One likely advantage at least of the orig. draft tube configuration, is reliably max. power (from a properly tuned/setup engine), since the atomized fuel is never diluted with bypass fumes.




6 VOLTS/POS. GRD. NW INDIANA

No, you would not typically throw away a 12 month old container of new oil.  One reason engine oil changes are recommended far more frequently than gear oils and transmission fluids is that engine oil is subjected to much more contamination due to the combustion process.



Lawrenceville, GA

I appreciate the input, but I don't believe modern oil is only good for one year, unless it is being contaminated. We wouldn't throw away a new container of oil that was bought 12 months ago. Does anyone change their differential or trans oil every 12 months, even if it is low milage?
I've been doing the same with my 62 series Landcruiser for nearly 25 years. The motor still purrs and it's just under 330,000km now. Half of that milage was done in the first 10 years of it's life, after that the yearly driving dropped off.
I've had the Tbird 15 years, and it's still running smooth and silent. As silent as a solid lifter engine can be that is. LOL 
As mentioned before, I do the Tbird oil when it's not clear anymore. That's about 2500 miles.
They both go about 2-3 years between oil changes.
The one thing that I believe should be changed regularly regardless of milage is clutch and brake fluid. That seems to absorb moisture regardless of use. I do mine every two years.
Thanks again for the input from everyone.

Most people recommend changing the oil at least once a year even  the  mileage  does not warrant it.





54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

VERY unlikely, in a tube of such large ID.  
If you don’t drive it much, then you won’t suffer oil/dirt spray collecting on the undercarriage & body, nor sludge buildup due to no crankcase vacuum when idling, nor noxious fumes in your garage, which is what inspires most owners that convert to PCV.

6 VOLTS/POS. GRD. NW INDIANA

It's not worth changing to PCV. My car does very little milage.
The oil takes several years to change colour, then I give it an oil change. Also, I like the originality. 
You mentioned cleaning. Do they get blocked?

Have you considered eliminating the road-draft tube and doing the PCV conversion? 

There is no filter in the early bird draft tube (only used in a sedan) .The draft tube on a early bird attaches in two places = at the top in the valley and and at one of the bolts for the starter..  There really isn't a service to this except for cleaning.  If you get underneath most of it can be cleaned by using a brush  on a long piece or something like a gun barrel cleaning tool.  Harder to clean at the top because of the right angle of the opening.

While it can be removed with the engine in place, it is a bear, especially trying to get it back in because of the distributor.  I do not recommend removal with the engine in the car...


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

I have been lead to believe the draft tube filter should be cleaned. I can't seem to see anything in the workshop manual.
There is one bolt where it connects to the valley cover. Is it just remove that bolt, and it lifts out on the Tbird?
Thanks for any advice.