I just bought an White Bros.E2 slip on exhaust on Ebay for my 06 and the seller stated it was for a 06-07 yz450f. Well everything bolted up fine except for where it slips on to the stock head pipe. The WB muffler pipe was a larger diameter than the stock 06 head pipe and the stock clamp is too large, the instructions that came with thr pipe stated it was for an 07. what can I do to make this work? will an 07 head pipe work on a 06 head? thanks for any help with this.