Yes totally I've looked up those 1903 and also looked at the ones that PHR recommended and they both "advertise" right at about 391. I found out the springs that I have advertised about 382 over the nose. Again I think both of your recommendations are right on par from what my amateur unknowing research can pull up.. again going on the weight of both of your recommendations I am preparing for this. Also recommended to check what I have and I will do that before I pull the trigger on anything. again if you read their I was just trying to see if some Stars lined up. Like as in someone checked these and maybe someone's check the ones that came off of a roller Magnum Edelbrock head and said oh yeah they were installed at this height and they made x spring pressure out of the box? lots of people have done lots of things out here and quite possibly I was hoping that since PHR goes across probably 20 different kinds of heads all the time, he may have tested that spring as well and found they work well at the same common install Heights..