Mystery Part...

[BrianG]

Originally Posted by beanious

Any other ideas?

Personally, I'd ditch the electric fans and put a clutch fan on there and the proper shroud. ... Along with the inner fenders of course. That setup should cool you just fine, it is reliable and wouldn't really cost all that much to convert to. You can probably make a few bucks selling those electrics to someone with a race car who needs to save that few horsepower that a clutch fan 'may' rob.

[beanious]

So as an update, aparently this part goes by three names:
"lower valance", "bumper/radiator deflector" and "bumper filler"

Is is only avaiable for the 67 and 68 trucks.

So I my list of improvement are below:
Lower bumper filler (modify to install)
Aluminum radiator covers
Wheel wells
Install flaps on back of radiator shroud in all areas possible
Insert foam between the radiator support and radiator
Insert foam betweeen the radiator and the shroud

Thank you all for your help, I'll work on these fixes, get to testing and then post the results!

[BrianG]

I think I understand what you are trying to accomplis by adding flaps to the fan shroud, especially seeing the fan shroud that you are using, but something to think about also is that the more flaps you add, the more you are just making it a fan bracket and not a fan shroud. If you do too many, then the air might not flow through correctly. Unless, I'm just not understanding what you mean, or how you are going to do this.

[beanious]

Brian, you are right on point with me needing more air at speed. The flaps I am installing close with suction, ie with the fan running. Think of them as a one way valve. This prevents the fans from pulling in air from the back side of the shroud. Please see the pic. Thanks.