Originally Posted by CraigG

Yes. In fact, some closely centered twins such as the T-38 are actually considered "center line thrust". Being inside the fuselage is not the issue, but the distance the engines are from the fuselage centerline. It is a physics thing about moment arm and such. FWIW, I wrote a pretty good article on this subject back in 2010 for the JPO mag Contrails. Click on this link and start on page 9 if you're interested: http://www.jetpilots.org/contrails/Spring10.pdf

Craig

PS: Apologies again for thread drift