Is this oil fill tube factory?
 

Trying to figure out if this oil fill tube is factory. I've tried to find similar post but no results. This 350 engine came out of a 1970 truck with factory AC and PS. I know its typical to have a factory oil fill tube like this on the 71-72's with same options but this one is made different. The valve cover hole is the screw in cap type and this fill tube is made to do that, not the push in style.

Re: Is this oil fill tube factory?
 

Just a wild guess,but could be used for a C40-70 application

Re: Is this oil fill tube factory?
 

According to this page 3929746 is for 1968, 1969-70 366 or 427 engine from a medium duty truck:

http://www.gmpartswiki.com/getpage?pageid=63055

Re: Is this oil fill tube factory?
 

Cool, so it’s a factory part year correct. I’m not sure what model truck it came out of just that it was a 1970. It was pulled for LS engine swap at a car restoration shop. Thank you for the information.

Re: Is this oil fill tube factory?
 

Info in this thread indicates the tube my have been a 4X4 thing as well as some 2WDs.

https://67-72chevytrucks.com/vboard/...d.php?t=781386

Re: Is this oil fill tube factory?
 

Thanks for the link, I read through it. From my experience on these trucks I've found most original non-AC 71-72 engines have the push in style rubber oil cap on both left and right valve covers. The non-AC passenger side valve cover oil cap is located toward the front of the engine giving easy access for oil fill. The driver side oil fill cap is located toward rear and not normally used. On the AC trucks the compressor is mounted over top of the passenger side oil fill cap location so its factory deleted (no hole, no oil cap). This causes the driver side to be used for oil fill and the factory oil fill tube is added for easier access. Typically most AC trucks had power brakes which caused limited access to driver side oil fill cap also. I've seen this on both 2wd and 4wd 71-72 trucks. The 1970 model engine I posted pics of above followed this same method but I had never seen this style oil fill tube before. With it being pre 71-72 and the screw in style oil cap valve cover, it made sense for it to be factory but I was unsure. Thanks again for your reply.

I should also note the differences I see between the 71-72 oil fill tube and the 70 oil fill tube in question pictured above. The 71-72 oil fill tube looks similar except for these noted differences: the 71-72 support brace is welded to tube, not clamped like pictured. the 71-72 tube will push in valve cover, not screw in like pictured. and the 71-72 oil cap will push in, not screw on like pictured. The 71-72 oil fill tube uses the same rubber push in oil cap as used on the 71-72 valve covers.

Re: Is this oil fill tube factory?
 

Look up the suffix code on www.nastyz28.com and it will tell you what that engine came out of

Re: Is this oil fill tube factory?
 

72chevynut, your research has clarified something for me. My 327 came from an A/C car and has just the driver-side fill cap, but my truck is non-A/C. I wondered why putting oil in was such a pain. Now, I know. I ought to look for one of those fill tubes to make it easier ;)

Re: Is this oil fill tube factory?
 

Jason Banks - Using your link and doing a little more searching I found same part number 3929746 listed used on 1970 Ser 10-20 (4/WD), Blazer (4/WD) w/BB (8 cyl.). I'm not sure what the BB stands for here, it shouldn't be big block because the 4WD models didn't come factory with them. My guess is “with brake booster”, would make sense due to the power brakes was a option then and would limit access to oil fill cap.

http://www.gmpartswiki.com/getpage?pageid=220375

Re: Is this oil fill tube factory?
 

Another option would be replace right side valve cover with one that has the oil fill hole and cap.

Re: Is this oil fill tube factory?
 

Thank you, I mainly just wanted to know if the oil fill tube was a factory produced part and if it was correct for 1970. With all the help and research looks to be all factory correct except HEI. I checked the engine code also - V0219TAY

V = Flint
02 = Feb.
19 = 19th day
TAY = 1970 350 engine, 255HP, 4bolt main, K-10 to 2500 truck

I didn't see any VIN stamped on the engine pad for vehicle ID it came out of.

I added some pics for reference: AC compressor is off due to weight limits on stand. Engine has correct clutch fan on it now. Clutch fan came with engine but the water pump/fan stud bolts had been robbed, Lol. Finally found some in my parts stash.

Re: Is this oil fill tube factory?
 

The rod that it is attached to from the intake looks like a repurposed firewall support for the power brake boster. I have one in my 1972 GMC, bolted from the front of the booster to the firewall.

Gary

Re: Is this oil fill tube factory?
 

Yes it’s similar to the brake booster support rod but different in length and attachment ends. This rod shows no signs of modifications. The oil fill tube itself looked modified with the welds located around top and bottom. After finding this oil fill tube part number listed for 1970 K series trucks and blazer I believe it to be factory first style for our trucks.