I don't have any response for the Seafoam. The throttle body gasket can be reused. The Service Manual says to use a new gasket. Your call. I just inspect mine to see that it is clean, undamaged and is still flexible. I would suggest getting a new gasket, just in case the old one is bad. At a Dealer (part number 24100165), the price will be $5.52. FelPro, a respected aftermarket gasket maker, makes a throttle body gasket part number 61337. Advance Auto gets about $3.29 for one.