I am installing a new exhaust system in my 1957 B20 GTS. It is the originail equipment version of the exhaust with two silencers on each side (the car currently has an aftermarket exhaust with a single silencer on each side). The new exhaust came with eight springs. They are identicall in size. Four of them are "hard" springs (heavier guage) and four tof them are "soft" springs. Are the two types of springs correct and, if so, how they are fitted to the car? Thanks.