Fitting an X-OST on a 308 QV

Need help here. I installed a new exhaust on 1985 308 QV an really love the low note (more user friendly for long drive than Tubi in my 355). The problem came from the excessive thickness of the new "donut" which seemed to have offset the new system towards the driver's side. The exhaust housing is almost touching the tailpipes. I will receive my Hyper-Flow soon and I now wonder if this will offset the muffler even more. Anyone out there had similar problem or would know where I could find thinner gasket(s). Sorry if this post sounds redundant but I didn't get much answer from previous posting .Thanks anyway and b.t.w. NEVER EVER try to thin out an exhaust donut on a lathe!