What is This?

[1966 LWB]

I have a 1966 p/u with the original 283 in it. When I got the truck it had the original chevy valve covers with no holes and the oil filler was on the intake. I have since replaced the intake with an edelbrock perfromer and the valve covers with chrome edelbrock pieces. The valve covers had one hole in each so I put a breather in one and an oil fill cap in the other. I noticed something odd when I was replacing the intake. On the rear of the block next to the distributor was a hole with some sort of fitting on it and a 1/2 to 1 inch rubber hose that came off of it and had been cut off by the transmission. What does this hose do? Can I remove it, plug it? And if I remove the fitting from the block there will be a hole there. Is there something made to plug this off? This is my first older vehicle to work on and I am stumped. Any help is greatly appreciated.

[low 84]

sounds like where the oil pressure sending unit goes. it screws into the block, to the right of where the distributor is. do you have an oil pressure gauge and does it work? i'm betting you do have one and it dosen't work b/c its not hooked up.

[1966 LWB]

No I have autometer gauges and installed the sender where the factory one came out of. This hole is behind that and is about a one inch hole and the fitting is kind of shaped like an egg and is about 2 inches tall. It has a bolt going through it into the block and then that rubber hose comes off of the egg shaped fitting to run down the rear of the engine.

[low 84]

hmmm sounds confusing, a picture would help

[lolife99]

That hole was for a crankcase vent. Kind of an early style pcv valve system. You need to put a late model pcv valve (67-72 pickup) in your valve cover to vent the crankcase. I would remove the fitting and install a freeze plug in the hole,... otherwise it will leak oil. Later model engines eliminated this vent.

[1966 LWB]

Thanks for the info lolife99. I will install a PCV and plug that hole.