These pistons are a drop in replacement for aq151 or aq171 Volvo penta motors. These motors are 2.5l and have a 86mm stroke vs the 2.3l motors that have a 80mm stroke. These pisons feature valve reliefs for the 16v head in order to fit both the 171 and 151. If you are building a performance motor please look to our piston sets that use a 158mm forged connecting rod. The default size on these is a 96.5mm bore, we can do them in 97mm if need be. Leave a note during check out or contact us..
As with all of out piston sets these will require upto 6 weeks to make.