Ok guys im new at this prop stuff and dont understand it, i just bought a 1976 glastron V-174 with 140 hp omc in it it came with 2 props a 14x14 and 18x18 the 14x 14 was on it but had alot of niks in it so i am wonder what happens when i put the 18x18 on it i have yet to run this boat so any thing would be of help MANY THANKS 