C1 327 oil pressure line fitting size

[Chris H.]

I was installing my original oil pressure fitting into the rebuilt block and it fell into the hole. I had to fish it out with a wire. I swear I took this same fitting out of that hole a year ago. It is located forward/left of the breather tube.

Found that the hole is a 3/8-24. Does this make any sense? Is there any reason the rebuilder would have tapped in a larger hole?

What is my solution? Are there larger fittings available or some kind of adapter?

Thanks, Chris

[Craig S.]

Re: C1 327 oil pressure line fitting size

Chris - there are pipe thread adapters in brass that you should be able to adapt with, I am not sure what the original hole size is or was, I can't see why the rebuilder would tap it out though......so maybe there was an adapter in the block before....Craig

[Chris H.]

Re: C1 327 oil pressure line fitting size

Thanks Craig. I dug out my old non digital photos (wish I would of had a digital camera last year!)and I have one where I can see the adapter. I went to Paragons web site and I see that later vettes, per their info, used this adapter.

Did '62 340hp use the adapter?

Thanks, Chris

[Craig S.]

Re: C1 327 oil pressure line fitting size

Chris - I honestly can't tell you, I have midyears and a shark. But it sounds like you need one ...Craig

[Pete Van Seggern #30920]

Re: C1 327 oil pressure line fitting size

I'm pretty certain that the hole in the block is 1/8 tapered pipe thread. 1/8 pipe measures .405, slightly larger than 3/8 (.375.) Also, the pitch of 1/8 pipe is 27 threads per inch, not too far from the 24 you mention. It would appear that you tried to check the hole with a bolt, and yes, 3/8-24 is as close as you can get. Maybe you got the wrong fitting?

[Jerry C.]

Adaptor

I had the same problem and had NAPA order the adaptor. It's a weatherhead product. I bought several and if you can't find one I can send you one. I think all small blocks with gauges had them.

[Chris H.]

Re: Adaptor

Thanks Jerry. After figuring out that I needed the adapter I dug thru some "extra" parts bag that I had and found the adapter.

(the extra parts bag is only a small baggy:))