I was going to respond earlier Roger, but didn't because although I am running a similar setup in my 27 I don't have the metal pan between the trunk and cockpit, mine is fiberglass and wood.

But, there should be no magic to this either way. All you want to do, or all you CAN do is try to seal off the bulkhead as well as possible to give you as much protection against splashed (in a rear end collision) gas as possible. I think we all remember the Pinto gas tank situation, but in reality very few cars from that era had better protection. Look at where a stock 32 gas tank sits, right back where a rear ender would smash it.

If it makes you feel better you could do the caulk routine and possibly lay a layer of some fire retardant sheeting over it. Not sure what that sheeting would be, but if you cruise the aisles at Home Depot you might find something suitable.

In reality though, most of our cars are vulnerable if some SUV rearranges our backside. My 23 has 11 gallons of high test sitting right where a high bumper would smash it and toss gas all over me, I'm sure. We have very little protection from some of the monster trucks running around on the roads.

Don