The only company I've found that has coil over springs that actually check close to the advertised rate is AFCO...and their batting average isn't perfect!!!! As an old dirt burner, I still have a spring tester around....some of the spring rates are real laughers---recently checked a brand new pair that were rated at 200 lb. non-progressive springs. One checked at 185, the other was 205---would have been fun getting that one to ride good!!!!!

If there's a dirt track or road race shop anywhere in town it's well worth your time to get the spring rates checked before you go batty trying to make a non-matched pair work... Don't know how it transfers to street or drag use, but on our last circle burner the AFCO's and Tru-coils were the only brands who held the rating after some use....