Yet another noob question...attaching a shroud to a heater core

[Bugsmasher]

Howdy all,

Finally found that 1977 Pontiac Bonneville heater core and I am looking forward to getting it installed into my w/c setup.

I made my own shroud out of some acrylic I had which has the fans at about a 1" standoff from the heater core itself. I did this to allow the air pressure between the fan and heater core to equalize and spread the airflow across as much of the heater core as possible.

Here is where I run into the problem.....how to attach the shroud to the heater core. I know the core/shroud combo I ordered last time came with some small size 4 all threads which can be used BUT the spots where there all threads belonged had already been modified by the supplier. With my '77 core that has not been done and I am a little worried about forcing something between the fins which might damage them. I know I could use some form of zip tie setup but am wondering if anyone has come up with anything better or has another suggestion. I vaguely remember seeing some nylon pull tights (like zip ties but they were straight with a 'bolt and nut' type of application) that actually went through the fins on the core and then through the holes on the shroud but unfortunately have lost the web address of the company that offered them.

If you have any suggestions it would be most appreciated. I have the basics needed for modifying the shroud as needed and dont mind a lil craft work to get this setup correctly.