1971 LT-1 plastic tee

[Mike E.]

My 1970, 1973, 1975, and 1980 parts books all agree that the "T" above the pcv valve on the left valve cover should be part number 3970076 (group 1.745). The AIM doesn't help, because in group 6 (engine) page C3 it doesn't show a part number, but it does refer to AIM UPC 8D. Sheet LT1 B2 has another hose routing schematic, but no part numbers.
Question 1: Does anyone have a 1971 AIM with sheet 8D? (Mine only goes to B7)
Question 2: Assuming that 3970076 is the correct part number for that fitting, what does it look like? There are NOS ones floating around, and the picture in Doc Rebuild's catalog correctly indicate a T with different size hose inlets in each end. The one in the attached picture is off a 30k-mile 71, toward the end of production. It has a definite plastic flange that acts as a hose stop for the hose coming from the front of the car. Does anyone have an unadulterated 71 LT-1 that could check to see what they have on theirs? Yes, I know the question is picky, but I'm still interested to know what is right. Or did two different suppliers supply parts that met the specs, and one had a flange and one not? Sorry the picture is not clearer--only one I have.
P5220965.JPG

[Terry M.]

Re: 1971 LT-1 plastic tee

My 1970, 1973, 1975, and 1980 parts books all agree that the "T" above the pcv valve on the left valve cover should be part number 3970076 (group 1.745). The AIM doesn't help, because in group 6 (engine) page C3 it doesn't show a part number, but it does refer to AIM UPC 8D. Sheet LT1 B2 has another hose routing schematic, but no part numbers.
Question 1: Does anyone have a 1971 AIM with sheet 8D? (Mine only goes to B7)
Question 2: Assuming that 3970076 is the correct part number for that fitting, what does it look like? There are NOS ones floating around, and the picture in Doc Rebuild's catalog correctly indicate a T with different size hose inlets in each end. The one in the attached picture is off a 30k-mile 71, toward the end of production. It has a definite plastic flange that acts as a hose stop for the hose coming from the front of the car. Does anyone have an unadulterated 71 LT-1 that could check to see what they have on theirs? Yes, I know the question is picky, but I'm still interested to know what is right. Or did two different suppliers supply parts that met the specs, and one had a flange and one not? Sorry the picture is not clearer--only one I have.
[ATTACH=CONFIG]58252[/ATTACH]

My 1971 AIMs stop at UPC 8, Sheet B7 also.
I don't think you will find that T in the 1971 AIM because 8B7 shows as 3991443 Hose ASM; meaning all three hoses and T came to St Louis as an assembly.

The 1970 AIM in the NA9 section shows all the hoses and T as separate pieces. UPC NA9; Sheet A4 shows the T as part number 3970076.

I think we know someone who has a stash of very original early C3s for your perusal in East Dundee. I think you know how to connect there. If not, you have my email and we'll make it happen.

[Patrick H.]

Re: 1971 LT-1 plastic tee

I have photos of the one on my 72, if you care, and my original mid-June 71 fitting is likely in my basement should you wish a photo. I would suspect that a base motor car would have the same fitting as an LT-1.

Patrick

[Kevin G.]

Re: 1971 LT-1 plastic tee

I'm posting the the pictures to add to the OP's question. The first photo is from my 71 bb, it appears to have some type of glue/sealer at the connection? The second picture is from the 72 LT-1. The 72 has a clip at the top, misplaced on the 71 or vs.?

[Paul O.]

Re: 1971 LT-1 plastic tee

Mike

Here is one on the bay 131411621056. That is what I remember them to look like.

Paul

[Joe L.]

Re: 1971 LT-1 plastic tee

Mike

Here is one on the bay 131411621056. That is what I remember them to look like.

Paul

Paul-------



I have several NOS examples of the GM #3970076 and they all appear just like the one in the eBay item so there's no point in my posting photos.

The 3970080 had 2 barbed 3/8" tubes and 1 barbed 1/4" tube. It was made of nylon plastic.

Keep in mind, though, that the 3970076 was a part released in 1970 and was available from GM until about 5 years ago. Over the 40 years, or so, of its availability it may have changed in minor ways. So, I could not guarantee that an original example found on a 1971 Corvette would be identical in every way to the part available at the end of its long tenure.

[Terry M.]

Re: 1971 LT-1 plastic tee

I'm posting the the pictures to add to the OP's question. The first photo is from my 71 bb, it appears to have some type of glue/sealer at the connection? The second picture is from the 72 LT-1. The 72 has a clip at the top, misplaced on the 71 or vs.?

Kevin
The 1971 picture has the clamp in the correct location. In the 1972 picture I can see the shadow of where the clamp was by the PCV valve. That yellow sealer is what the factory used. No clamps at the T itself.

[Kevin G.]

Re: 1971 LT-1 plastic tee

Thank you for the help Terry!