Just finished my '88 Tristar closed bow and replaced it bow to stern. I used a piece 8.5' wide by 18' that I split into two halves for the port and starboard pieces. I needed another 8.5 w. by 7' that was cut basically into four pieces for the three center panels and the drivers kick piece. One tip though, I cut the motor box piece, 10" x 13' prior to splitting the main piece in two.
I agree on the glue, buy a gallon of solvent (mineral spirits) and have plenty of rags. I just kept a rag soaked in solvent handy. Also, when wrapping the floor panels on the bottom, I taped off just inside of where carpet ended and then spread glue to the tape. Pull the tape and then fold the carpet over so no glue is left exposed to get onto everything else.
1988 Tristar 190 Sport, 351W w/GT-40's, 1:1 Velvetdrive