Discussion Forum - Northstar Chevelle Club

I think the Part number is generaly cast into the spacer, my 3814241 and 3876828 spacers both have the number cast into the part.. My book says 3857042 is 1 19/64". A pretty rare part. Believe it was used only on 396 engine with 325 or 360 hp cars without AC and with an optional fan shroud. Standard spacer with the 396 and 3 row raidator is 2 15/16 except when you had the fan clutch, so I would think something like 1 3/4" would also work unless you are using a wider 4 row radiator.

What about a fan clutch.  Think an original style is quite reasonable.

I have an original 3 row radiator.  I have never looked closely at the brackets that the shroud mount to on a 4 row radiator; but they would probably be wider since the tank is wider by about 1/2".

Originaly I started out by using the 4 blade fan with the shroud, so I had to find a spacer that was shorter than the 3876828 which is about 2 1/4".  First I tried the 3814241 ( quite common) which is about 1 7/8"; but that still had the fan blades too deep in the shroud.  Then I found a 3765386 which is about 2 5/8" that is off a 67-8 camaro I think that worked better.

Then I changed to a fan clutch from a 66 BB chevelle and that moved the blade back a little more.

I would think that if someone had a metal lathe, you could mill  an original longer one down to the correct dept; but it looks like the part that fits into the center of the blade would be gone if you did that, so you would have to somehow weld a piece with a width of 5/8"  in there to act as the centering guide for the fan blade.  Not to difficult with someone with you skills. 

How did you deptermine the  part # for the correct spacer on your application?  I couldn't find it anywhere in the 66 AIM or my books?  Do they make aftermarket spacers with the correct depth that you are looking for?  If so who, since I may at some time go back to the 4 blade fan?

Lost in the 60s wrote:

---

I got the part number out of the Classic Muscle catalog. I haven't looked for an aftermarket yet. I have a guy near me that has a mill in his garage. I will get over there soon and see if he can cut the one down that I have before looking at other aftermarket parts. The centering hole for the water pump boss is plenty deep enough to remove about 1/2". That should put me at about 1 7/16. I'm still waiting for a 5 blade fan from a guy to see how deep I want the blades to be in the shroud. The shroud is rather shallow.

---

 So your going to use a 5 blade fan that was used with the  fan clutch  instead of the 4 blade fan?  I have both in  the garage on a shelf.   Classic Muscle is where I have seen that part #; but I have never been able to determine what   application.

I think you have to remove the material from the fan blade end of the spacer if you are looking at an original gm spacer, unless you don't care about the appearance of the spacer or are using a non gm spacer.   Kind of interested myself in cutting a 2" original gm spacer down to 1 19/64" to see how the fan blade and shroud fit.

You could use my 5 or 4 blade fan and the 1 5/8" spacer for a test fit; but I would probably have to mail them to you. Not interested in selling the spacer as I may go back to the 4 blade fan and shroud.

jim larson wrote:

---

Just found the application for spacer 3857042.

Used when you got the V01 option (Heavy Duty Radiator) with RPO L34 or L35 only. You also got a fan shroud on both the L34 and L35. And You received the 4 row raidator on the L34 and the 3 row standard radiator on the L35. You would get the same shroud and radiators that came on the L34 and L35 with AC and Manual trans. With AC you also got the fan clutch. On Powerglide L34 and L35 with AC you got the 4 row, shroud, fan clutch.

There were very few cars that got the VO1 option, less than 100 comes to mind, so that spacer is quite rare.

-- Edited by jim larson on Tuesday 19th of April 2011 02:22:20 PM

---

That spacer was used on Camaros too in 67 and 68, and possibly Nova's so they are out there.

No way to use a fan designed for a clutch with a spacer. The spacer I have that I may cut down is an aftermarket, one-size-fits-all with slots for the bolt pattern. Not a huge loss if I wreck it...