/6 headers

Okay, my questions about these hedders. I have a set of long tube Hooker Super Comps for my slant along with an Offy intake and Holley 390. It appears that my Hedder flange is about an 1/8th of an inch thinner than the intake. I dont want to just use some small spacers to even out the gap. Does anyone make something kind of sturdy to aid in this. I am guessing thinning down the flange on the intake is not a good idea due to maybe the aluminum flange being to thin and cracking but again I am just guessing here. Any tips anyone?? Thanks.
Chas.