Fan shrouds

[rod1701]

What are you guys running on your 78-80?
My 79 came with a 2 piece held together with zip ties and held in place with bailing wire. No top plate or brackets.

Found a 4-row from a BBC Dually with top mounting plate. Shroud missing. Bought a 1-pc shroud online cheap.

Problem is, none of the shrouds mounting tabs match the top plate bracket I want to use.

Any pics or part numbers?

[Palf70Step]

The 2 piece shrouds are for the small blocks. They vary depending on whether you have AC or not or HD radiator. 1978 was a change year so 78 and up models are are one way and 77 and earlier vary also. The BB uses a one piece shround. 6 bangers also used a 1 piece, but that one is no longer in production and hard as heck to find one intact.
When I had my V8 square, I just bought a new upper and lower as I had the same issue you did.
https://www.lmctruck.com/1973-87-che...tor-components

If the zip tied one is in decent shap you may be able to get by with just getting the clips.

[Pontiac1976]

73-80 454 BBC shroud fits all 73-80 rad support. Info:https://bowtieguy.proboards.com/thre...nting-brackets
Now if your BBC rad shroud was a diesel you may need to rest of the set up that came with it. or make up a top plate.
As I did. I run my 77 3 core 454 rad on my conversion. now have changed over to a electric fan now. https://bowtieguy.proboards.com/thre...l-electric-fan
and no the zip tie gone they were there in mock up.

[demian5]

What the radiator is for does't matter, the truck can fit like 5 different sizes in the core support. If the small block radiator is same height and width as the big block one, the small block shroud works. And it should have a 2 piece factory.

[rod1701]

Ordered 2 pc. Replacement for 78-80 from LMC this weekend. Thanks.

[THI]

Originally Posted by rod1701

Ordered 2 pc. Replacement for 78-80 from LMC this weekend. Thanks.

Please let us know how it works out. I have a 1978 that the shroud is missing chunks!

[rod1701]

New 2 pc. Shroud arrived today. Went to mount it but still not lining up. Feeling pretty stupid about this but need some help.
Fan is 17.5”
Radiator center core section is 19”
Shroud opening 21”

Using the radiator mount shown below. When I bolt up the top of the shroud to the mounting bracket, the bottom piece won’t bolt up without hitting the fan. 2-3” difference.

If I put the shroud together in a position where fan won’t hit. I don’t have a way to mount the shroud.

What am I doing wrong?

Anybody have shop manual showing correct mounting for 1979? Pics are always welcome too.

[Pontiac1976]

Your top plate as looking @ it left bottom side to motor. If you look LINK: >>https://www.lmctruck.com/1973-87-che...tor-components You need the #7 two and #8 two at the top slides on the motor side of the top plate. you need #9 four for your rad two for the top plate, two for the rad support bottom support. You need #6 two for the bottom of the shroud they slip on the outer bottom corners in reverse of there pic. Then the bottom shroud slips over the bottom support edge close to the fan. Do not forget the two bottom #9 for the rad.
Your top plater rad four holes bolt to the top rivnuts .Then the two bolt from the top shroud in to #8 left and right # 8 slides on the top plate.
then you bolt your shroud together.

[rod1701]

Originally Posted by Pontiac1976

Your top plate as looking @ it left bottom side to motor. If you look LINK: >>https://www.lmctruck.com/1973-87-che...tor-components You need the #7 two and #8 two at the top slides on the motor side of the top plate. you need #9 four for your rad two for the top plate, two for the rad support bottom support. You need #6 two for the bottom of the shroud they slip on the outer bottom corners in reverse of there pic. Then the bottom shroud slips over the bottom support edge close to the fan. Do not forget the two bottom #9 for the rad.
Your top plater rad four holes bolt to the top rivnuts .Then the two bolt from the top shroud in to #8 left and right # 8 slides on the top plate.
then you bolt your shroud together.

Most all of this makes sense. I have new bushings (9) I have the clips and bolts. But when the top half of the shroud is in position to bolt to part 15, the 2 halves of the shroud dot meet up because bottom is hitting the fan.
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[rod1701]

Originally Posted by Pontiac1976

Your top plate as looking @ it left bottom side to motor. If you look LINK: >>https://www.lmctruck.com/1973-87-che...tor-components You need the #7 two and #8 two at the top slides on the motor side of the top plate. you need #9 four for your rad two for the top plate, two for the rad support bottom support. You need #6 two for the bottom of the shroud they slip on the outer bottom corners in reverse of there pic. Then the bottom shroud slips over the bottom support edge close to the fan. Do not forget the two bottom #9 for the rad.
Your top plater rad four holes bolt to the top rivnuts .Then the two bolt from the top shroud in to #8 left and right # 8 slides on the top plate.
then you bolt your shroud together.

Most all of this makes sense. I have new bushings (9) I have the clips and bolts. But when the top half of the shroud is in position to bolt to part 15, the 2 halves of the shroud dot meet up because bottom is hitting the fan.
Posted via Mobile Device

[Pontiac1976]

Ok do you have pic of you fan on the motor, and how far it hitting where. or do you know if you have the heavy duty cooling A/C do you have cond, in front of the rad?
I just thinking you got to big of fan or 5 blade or 7 blade long neck clutch or short neck clutch.

Because there a few different 2 parts shroud & clutches and fans that can be used.
your fan should sit a 1/4" inside the shroud to pull the most air in past the rad to cool it.

[rod1701]

Originally Posted by Pontiac1976

Ok do you have pic of you fan on the motor, and how far it hitting where. or do you know if you have the heavy duty cooling A/C do you have cond, in front of the rad?
I just thinking you got to big of fan or 5 blade or 7 blade long neck clutch or short neck clutch.

Because there a few different 2 parts shroud & clutches and fans that can be used.
your fan should sit a 1/4" inside the shroud to pull the most air in past the rad to cool it.

5 blade fan. 17.5” or close.
When I bolt the top piece to the metal plate and try to attach bottom half of shroud, it hits the fan. Lacks about 2” to meet.

Best pic I have is this one. Was trying to get it running to move for a construction project. Had to have it towed to storage lot for a few weeks.
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[Palf70Step]

You have a newer (88-94) style serpentine belt setup and probably a reverse fan that is sitting wrong for the squarebody shroud. You may have to modify/shift the mounting of the fan shroud down some to clear the lower edge of the fan. Either that or see if you can find a smallblock fan shroud for an 88-94 style GM truck. Again it will probably need modified to mount.

[rod1701]

May not be a good image but not a serpentine drive belt. One belt running alternator and smog pump. Second drives power steering. A/c compressor gone but there is additional grove for that belt.

It did have 81-87 shroud although it was beat all to hell and held on with wire.

I’m down to thinking it’s the wrong fan/clutch or much more likely operator error.

[Palf70Step]

Yeah I looked closer at picture. The belt sure looks wide to me. Yea, not sure what to tell you. I know the squarebody v8 fan I have is 5 blade and same size you mentioned. Do you have room above the fan to make the top piece drop some?

I don't have this truck any longer, but this is the fan shround that was on mine. it was an 83, but they pretty close for all years.

[Pontiac1976]

Those blades seem pretty wide. You should try putting on the bottom shroud first to find out if the blades clearing. Sitting in right place. You may have to change the fan blade to not as wide. Does the clutch sit in side the shroud mouth but not to close to the rad. the motor pulls up and back under load. Your fan has the tips bent forward I never seen a 73-87 Chevy 305,350,400,454 gas motor with that style fan. You may have to change it.

[Pontiac1976]

https://www.bing.com/images/search?v...=88&ajaxhist=0Here a pic of a 5 blade
https://www.bing.com/images/search?v...HaFj&mediaurl=Here a pic of 7 blade

[rod1701]

Based on some of the brackets, I have a feeling that someone robbed used parts from a 70s Impala or Chevelle. May be the case with the fan and clutch too.

[Pontiac1976]

https://www.bing.com/images/search?v...0DwHaFj&mediau
Here the un-bolted clutch from the water pump top four bolts then the fan four bolts. Should be 1/2" or 9/16"

[demian5]

There are many different setups for the brackets and radiators, but I believe the shrouds are all the same.

I always had a 21" 7 blade aluminum fan on my square body trucks. Usually ordered a Corvette fan. Never had an issue. But.... I had big block trucks.

If yours sits on the bottom bracket it hits or when on the top bracket?

[rod1701]

That’s my thought too. Should be basically 3 shrouds; 6cyl, SBC (2pc), BBC (1 pc.).

When top is mounted, the bottom is off the lower rest/tray but doesn’t want to mate up to top piece without hitting the fan.

[Pontiac1976]

Lets see if I got this right now.
When you in stall the lower section in the correct location at the bottom in the clips not touching the fan bottom,or sides.
Or when you bolt the top it does not hit the fan top or the sides correct.
So then this top plate not right for the shroud rad combo. You need the Top plate mount that has bolting holes about 2" lower on the shroud side. "For the 73-80 rad support small block Reg cooling" I'm guessing.
The one in the pic you said you have is mostly common for Big Block Extra cooling.
Now I know for sure that LMC does not sell all the top plate for the shroud. For the most
Part it's the most common cooling set up. I'm pretty sure there is two top plates they do not have, for sure that semi common but they do not have. You need small block and shroud to match you rad fan that your truck had.** or the RAD and fan top plate shroud you pick to fit.( has to work as a unit.) That why back in the early 2002 I keep the 77 454 shroud fan for the 84 rad support, but the 77 top plate would not be correct for the 84 support I got parts truck 6Cyl. The upper brackets are lower in all most all times Reg cooling 81-87 mostly Rads come short but wider. So I made up upper alloy rad support ran then for 2yr till one day I seen the big block that come with the old set up SB. heavy cooling the SB upper rad support higher shroud like the big Block. The only thing I did not have the top plate to work the 77 shroud. So the top of the rad would have 1"to 1-1/2" gap between the rad & support (inclose) to finish off the top. I look for a long time they were all was missing one part broken. After getting the SB 81-87 upper rad supports it looks factory again and works. Then I end up year ago putting Mercedes E Class electric PMW fan my rad a spare 454 shroud cut down and mounted fit nice.(looks like factory) Now getting back to shroud there is one shroud that if I remember right the top plate is molded in to the shroud hard to come bye. I think there is three SBC 73-80 shrouds. If I remember right I been long time. Since I was looking for them up here.There not as much around here as they where, most are broken or changed some how. Oh does your shroud match the LMC drawing.