I had a GT5 Mini, 1275 A series, probably about 135 HP. The PO changed rod and main bearings every three races. Good rods and pistons should be good for a good while, rings are another story. 6 -10 races if you don't run air filters, good bit longer if you use decent air filters. BMC A series are 3 main bearing cranks so you have to stay on top of bearing wear.