sinse the introduction of the 31 sonic ( 1994?) has there been any hull changes and what were they ? on the sonic web site there is a review on the 1994 sonic with 502's and said it went 74.4mph is the newer design if any faster with this engine package ?

The biggest change Sonic has made over recent years is with the process in which they make the hull, not the design of the hull. This process didn't change the lines that I'm aware of, however it supposedly decreased the overall weight of the boat... I have never heard any real weight numbers since they began the new bagging process. Expectations were that the boats would decrease weight somewhere under 10%. I believe late 2001 or early 2002 is when they started producing boats using the new process. By that time, they started using the 496's. Other than cosmetic changes, placement of internals, I'm not familiar with any major line changes to the 31'. Maybe some of the ling timers here know of something...

as far as I know the hull remains the same...Dano would know for sure.