Radiator Fan/Clutch/Shroud questions. What do I do???

[goathearder]

Hey All,
So I have a 73 K5 with a 91 front end swap and I need help with my cooling system. The PO put in some stupid tiny little electic fans and I need to ditch those cause they are not cooling adequately in off-road situations. I want to go back to a standard mechanical fan for simplicity and reliability but I have a few questions:

1) I found a shroud at the JY that fit to my radiator top bracket so I am good there. It has about 9 inches from the center of the water pump to the bottom of the shroud so I assume that means I need a 18 inch fan. I also assume I need a clockwise one (standard rotation). The real question is do I need severe duty, standard duty, or heavy duty?

2) This brings me to the clutch, do I need severe, standard or heavy duty (assuming it matches the fan choice). Do I even need a thermal clutch at all or does a non thermal clutch work too? What came stock on the 73?

3) I am putting in a new radiator too, looks like they were all the same size from 73-91 but do they have the same mounting??? Do I need either the 73 or 91 or will both work? Will the support pads from either work as well? Should I get a 2 row or 1 row? According to the website they both have the same thickness so what is really the difference?

4) Lastly, is it ok to run the radiator top bracket and shroud from a 73 on a truck with a 91 front end swap? I don't see why not so long as everything is centered but I just want to make sure.

I know this is a lot of questions but I am very confused so any help will be appreciated. I also have a winch mounted on the front now if that makes the fan/air requirement any different.

Thanks,
John

 

[blazinzuk]

To run the shroud in the right spot and have everything situated normal, you need the mounting brackets etc from the newer truck. The little rubber pads will work on any year, but the actually mounting bracket is completely different between the early models and the late models.

If you have not found out yet the LMC catalogs are a great reference guide. Look them up, they have diagrams for all the parts you are going to need and the physical differences in them.

As far as fans go I like clutch fans. Why, seems like a good idea is why. They are more expensive than a normal flex fan.

If you are not having or did not have any problems with cooling then I would run the stock style and size radiator, not the bigger one, with a shroud it provides good cooling for a stock motor, if your motor is modded then I may upgrade or if you plan to mod your motor at a later date.

 

[goathearder]

So will the shroud from an early model work with the brackets from a later model? I was looking in the LMC catalog and that is what got me all confused, hahahahaha.

I can't tell from the pictures if the shroud from the late model has its holes in the same place as the shroud from an early model.

I was only having cooling problems in continuous low speed off-roading situations so that is what I want to fix the most. I think switching back to an engine driven fan will be a tremendous help there but do you think I should go with a standard duty or severe duty clutch? The truck is by no means a race car so I am not concerned with losing some power but I do eventually plan to mod it a bit so I wanna make sure I have enough cooling capacity for the future.

Does anyone know what kind of clutch the high capacity cooling package came with? My truck will eventually have AC too so I want to make sure that is gonna work as well.

 

[blazerbones]

If your main concerns are cooling at low speed and cold air conditioning at low speed I would upgrade/repair the electric fans and "shore up" the charging system. My 2cents.