I am doing a 5.7 with 545 build also! I am going to use a SHARADAN PERFORMACE built tranny with a stand alone trans controller and a paddle shifter. THEY BUILD THE TOUGHEST 545 TRANNYS OUT THERE IN MY OPINION! They had a guy that ran the baja 1000 with one of their tranny's shifting it with a paddle shift up and down between 4,000 to 7,000 rpms the whole race! After the race they sent back the tranny to be inspected. it checked out fine and was reassembled with the existing parts and was used in several smaller races. If you have a transmission question or if you put some power to your tranny and it breaks give them a call 651-426-0061 ask for Denny. Is the gas pedal going to work out it looks real close to the tunnel? Nice build keep updating the progress!