A few questions. We have our 406 engine back without an adapter. A friend gave me a stock GM one however I dont know if it requires special bolts or not,and it doesnt have a bypass valve just a hole in the adapter piece. Was the spring valve supposed to be in the block or ? I guess I could plug the hole so all oil is forced through the filter although there appears to be some differing opinions on that one. We are using a Mellings 10552 which is supposed to be 10% greater than stock. Also the adapter can be bolted on in 2 ways does it matter which way the bypass hole in the adapter faces. TIA I havent worked on this area before and cant cant find anything in my books or the net.

The hole should have a disc in it and a spring keeps the disc shut.
I always face the bypass to the outside of the block... further from the inlet passage.
I would not block the relief hole.
It does not require special bolts, they are 5/16 coarse, and approx1.25" long. Some (older)cars had 7/16 bolt heads, the 80's cars had 3/8 heads. Neither had lock washers.

Micky,
Like Dale said, the bypass should be in the hole in the mount. I will disagree with Dale on the bolts though ... they have been the same for as long as I can remember and they are a special bolt with a smaller head than normal so you can get a socket on them easily. Your machine shop probably has a box full of adapters and bolts they have saved off junk engines. They are still available from GM for less than $20 for the adapter and bolts.

Remember that you have to use the stock can by-pass valve casting UNDER an aftermarket spin-on oil filter adapter or the oil won't flow right through the filter!!

Right BillK..........

And I use the old can filter b/c it flats works good to me even though it's a mess to clean out every oil change as well as have to use an ice-pick to get the big o-ring outta the groove!! It's worth it to me!!

pdq67

My machine shop recommended a B.A.B.E. "billet aluminum bypass eliminator". I often take out the spring in the stock adapter and fill with j.b. weld because within time the spring gets weak and some of your oil doesn't get filtered! If you change your oil regularly you don't have to worry about anything. I think you should fill in the bypass hole.

And when your engines cold, you run the risk of blowing a filter IF you wrap her up before the oil thins down too!!

pdq67

Thanks for the info