Aftermarket Header installation problems

[hitorque250]

Hi

I am in the midst of restoring my grandfathers pick up. I left the six (250) in for the sake of memories. I wanted a little more out of it so in addition to an overhaul, bigger cam, offy intake, and Holley 390, I installed a set of headers. The problem is that the original fasteners don't fit with the aftermarket headers and intake. I used large washers and bolts instead and still the headers pull free and have made a nasty spot on my new paint job. How do some of ya'll have your headers and intakes fastened?

Thanks a bunch!

Will Hill