Upon revisiting this solution I decided to contact McMaster-Carr, however when I did so the gal on the other end didn't have any info about the item I asked about -92805K23 a Silicone cap High Temperature Round Silicone - It looks too thin along the sides to hold very long - Maybe John will see this and reply - Hope so! Thanks!
Great info regarding the caps! And the Silicone caps from McC would fit the bill more than likely. I went with the 2" piece of radiator hose and a #8 bolt for $2.80 -Thanks!