Hello, so I have searched all previous threads on this topic and could not find the specific answer to my question, so here it goes

My 64 F250 has it's Y block out getting rebuilt. After smoking myself out at a light, I've decided to ditch the draft tube. I bought a PCV conversion for a 57 Thunderbird, this kit eliminates the draft tube with a grommet in the valley cover, pcv valve up to a hose and into a supplied carburetor base plate.
my question is do I leave the vented oil fill cap, or do I have to switch to the non vented with a hose to my new air cleaner?
Thanks in advance!

 

No FoMoCo vehicle had PCV until 1961.

Upper pic: 1961/63 is the same. The 6A665 adapter replaced the road draft tube.

 

I know, it is a kit I purchased through Hills Automotive in Ohio. Converts 57 and later y block (4 barrels) to pcv.
so the pictures are a help but leave out the oil fill cap, still not too sure about vented or non vented.
I understand that in order to evacuate Crankcase pressure, fresh air needs to come in, but is the vented cap enough or does it need a feed line from the air cleaner?
Thanks

 

Either way will be vented and either way will work fine. The difference is that the version with a hose going to the air cleaner is a closed system, which helps to prevent fumes from venting to atmosphere - an emissions thing.

 

Clean air from the air filter Is my preferred choice. Those caps with filters in them need constant maintenance to keep them flowing, when is the last time anyone cleaned one?

 

Perfect thanks very much guys! I'm not a huge fan of the long hose to the air cleaner but it does seem like the better of the two if they both do the same thing.
cheers!

 

My f350 has a 62 engine in it. Before rebuilding it the engine had a pvc system that used the front vacuum port in front of the carb. I installed a valley cover that was modified to have the pcv valve directly sticking into the valley from where the road tube had been. My hose still goes around to the intake in front of the carb. From other posts I've read I would keep the vented fill cap because the valley cover has a piece that goes across inside that blocks/limits the draw on the front half of the engine. So the pcv is basically drawing against the back half of the engine.

 

I actually have the 6A664 PCV in my 64 F250. It runs with the vented cap on oil filler tube, one of the posters is correct, keeping a clean fill tube vent is good practice. Most of us that own these old machines are (I think) pretty meticulous with maintenance anyway, but it was a good tip.

 

Here's the valley cover I used on my pcv. This unit was on a 312 that I bought that had a cracked block.