V-8 Fan Shrouds?

[CG]

Are there only two style V-8 shrouds?

One size for small block and one for big block ... I don't believe the 4x4 has its own third size correct?

I'm trying to make sure I have all the parts for my burb and panel and don't accidentally let them go.

I have this core support with all of the air con stuff attached to it, couldn't remember where it came from so I put it in the to go pile. I was sitting here the other day and went dang that was close, that's off of my burb. I had forgotten I brought it home from where the burb is getting body worked and painted.

[Mike C]

IME you are correct. Small block and big block 2 wheel drive then small block 4 wheel drive.

[Stocker]

I'm not familiar with big block applications but I will say the shroud for a 4x4 is deeper than for a 2WD truck. Wouldn't swear to it but I believe it's because the engine sits farther rearward in a 4x4.

[FirstOwner69]

Here's a picture of 2 small block shrouds back to back showing that the only difference is that one has a longer "snout" (about 3/4"). My understanding was that this was to properly position the fan in the shroud dependent upon use of a fan clutch. In other words the short snout would be used when the truck had A/C, and the long snout was used when the truck did not have A/C.

However, Mike and Mike have a good point. So, was there third small block shroud for a 4X4 without a fan clutch?

[Stocker]

Dunno about non-A/C trucks with fixed-blade fans. My K20 has factory A/C which includes a clutch fan. The OE shroud measures about 9 1/4" front-to-rear at the top of the shroud.

[LockDoc]

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Big block shroud is different than small block shroud. This is big block shroud.....

LockDoc
'

[special-K]

Didn't all V8s come with fan clutch? I never saw the clutch as an option and have never seen an original w/o the clutch. I don't believe there was an optional fan at all, only optional radiator in the cooling options. But I never knew there were two different small block shrouds either, so...

[uncle]

Tons of v-8’s w/o fan clutch especially if no a/c. I’ve probably had 30-40 w/o clutch. There is also a 6cyl shroud similar to the V-8 pictured above but even shorter.

[special-K]

Originally Posted by uncle

Tons of v-8’s w/o fan clutch especially if no a/c. I’ve probably had 30-40 w/o clutch. There is also a 6cyl shroud similar to the V-8 pictured above but even shorter.

Learn something everyday. I have owned and seen tons of these trucks myself in the 50 years I've dealt with them and never knew that. Most I've had didn't have A/C, too, but they all had a fan clutch. I used to run flex fans which meant using a spacer in place of the clutch. I guess I assumed the ones with spacer had the clutch removed. I need to check my shroud stash for differences. I assumed they were all the same. I wonder how many trucks I ran using the wrong shroud. I always figured the spacer equaled the length of the fan clutch. Never had any issues either way

[Steeveedee]

I recall reading that the AC trucks had a bigger fan (19", Vs 18"). It was in the document that specs out what gets installed with what options, but I can't seem to find that document, now. I buggered up my shroud trying to get the opening closer to the radiator so that the fan would couple better. When that didn't work, I made my own shroud out of aluminum, and got a 19" fan to go with it.

Does anybody have that document? I'm not sure what to call it, maybe "ordering guide"?

[Stocker]

Originally Posted by Steeveedee

I recall reading that the AC trucks had a bigger fan (19", Vs 18"). It was in the document that specs out what gets installed with what options, but I can't seem to find that document, now.

If I am wrong, someone will correct me but I am pretty sure big-blocks came with a 19" fan, and small-blocks, A/C or not, came with an 18" fan.

[Steeveedee]

I'd swear I read it in some literature. Maybe that is what it said, and I'm not recalling it correctly. That said, the original fan was 18", with a factory big block that came with AC. There was a big gap between the fan and shroud all the way around, originally. My FiL fought running hot with that truck from day one. He bought it at three years old.

OK, I searched around, and believe that the document is the 1970 Chevrolet Truck Data Book. Only place I can find one is on eBay for $250, and I ain't spending the money, since I could be wrong.

[Steeveedee]

C'mon, somebody has to have the page of some document that shows fan sizes. I'm hoping...even if I'm wrong!

[geunther]

There is also some difference in the shroud depending on which radiator is installed (two vs three core) on a small block. When I had my radiator re-cored, I added a third core. The original shroud was now too close to the radiator, considering where the mounts were. To be fair, I don't know with certainty that the difference was in the shroud but I had to add a spacer to move the shroud further back. The difference would be between the mounting surface and where the shroud contacts the furthers back core.

[Grumpy old man]

There were 5 different fan shrouds avilable 67-72 from what I found when I was looking for my 67 small block stock location , I used the 32-2825 From LMC , They had the best price at $49.95 with an 18" 6 blade fan and hayden clutch and the Champion CC369 radiator . fits great .

6 cylinder with automatic trans / rare / no longer produced . Most have the finger guard

32-2820
SHROUD WITHOUT AIR CONDITIONING SMLBLOCK V8
2 WHEEL DRIVE 67-72

32-2825
SHROUD WITH AIR CONDITIONING SMLBLOCK V8
2 WHEEL DRIVE 67-72

32-2826
4 WHEEL DRIVE 67-72

32-2828
SHROUD 396 402
CHEVY GMC 68-72.

[special-K]

Now I'd like to see the specs on the full variety to know what is what when I'm looking at shrouds. I just happen to have a shroud garden growing out back. I moved everything stashed in my screen house once I finished moving my barn. Haven't dealt with the shrouds yet

[uncle]

There was also one for the V6 which some are the same as Big Block and some are a little different.

[Steeveedee]

Given the pictures I'm seeing here, and until I see that data book, I'm going to have to say that a large part of the problem with my truck running hot most of its life was from having an 18" instead of a 19" fan installed. It'll be interesting to see what else comes up about this. My truck no longer runs hot, but I may have committed overkill in the process of getting it there. Next up is fixing the AC clutch and getting the AC working during normal driving. My wife was 16 when her dad bought this truck, and because of the heating issues, they didn't ever use the AC. She was surprised that it even had AC, when I told her that I had charged it.