Hi All: I have a ST .49 engine that looks like the ST .51 that Brian Gardner is making .51 pistons and cylinders for stunt use. Will his .51 parts fit into my .49 engine ala Fox .29 and .35 Stunt engines from yesteryear? Perhaps the cylinder walls are a bit thinner to make the .51 displacement. I have been told that my .49 ST was only produced for one year. Both my .49 and my friend's .51 are excellent Stunt engines. Any insight about the p&C swap or when the .49 was produced? Tia, Frank McCune