for 750 psi ...do you think that would be worth the time you spent getting it in.

or how much would you be taking away from the tube, when you drilled it to get it in? Even if you tried to weld it shut after ... have you ever tried to weld around A-B foam ... it mite as well be gasoline!!

I dont disagre that it would add ...a very little ... but anyhting you add would incress it. Fill it with water and frezz it ... If it didnt pop the tube ... I bet that whould add to it also.