I was gonna try using an oil filter seal, but it looked way too thick to me... I didn't want to risk blowing it out. Instead, I just went to a local Autozone and bought a big O-ring that matched pretty close.
thats what i did - i matched it up pretty good to one of the same width [there are different widths... i think i used a o-ring from a fram oil filter] - Its been on for 3-4 months - Absolutely NO problems and only spent $3.XX :biggrin: