so i would like to make some ducting for my coolers but have no idea what i need besides sheet metal and rivets besides fabbing it up out of cardboard before doing it, how do they mount up on the coolers itself?

 

On the stock coolers, sticking out on the front side, there is a tab toward each end above the core and one below the core near the center. Plastic push fasteners mount the duct to the cooler through these holes.

I'm not especially experienced at metal work, so for me it would be easier to make them out of fiberglass by fabbing a wood mold, waxing it, and then doing layups on the mold to make the ducts. But, if you're good with metal maybe it won't be difficult.

Last time I checked the oe ducts were about $45 each.

 

You don't have the stock ducting...is that what you are saying? Or modified or added a non-stock system?
What do you want your ducting to do...as in, where do you want the airflow routed?

 

I have aftermarket coolers setrab 25 row. So oem won't work. I just want to direct more flow to the coolers instead of leaving it open. What type of sheet metal would I need and how would it be held on the cooler are my main concerns.

 

Ah! I see now.
It is going to take some...engineering...to not give it the 'Afro-American Customized' look, for sure.

 

6061T6 AL .032" is a good start if you can find it.

I made mine from scrap material at my work. I sheared it into pieces and used some bent pieces with fasteners to hold it all together. I made the top piece and bottom piece to hold onto the cooler with fasteners.

 

I haven't made custom ducting for the oil coolers since I have stock units but when I was making my I/C duct, I mocked everything up with cardboard cutouts taped together and used those as my template to cut the sheet metal. If you don't have access to a welder, you can add tabs to your sheet metal and rivet the pieces together.