just replaced my radiator and i noticed that my stock rad cap doesn't fit...went to buy another cap and told parts guy that it's for a 94 integra rs but that too didn't fit...called the place i bought my rad at and they shipped me a rad cap that fit...my problem is the cap pressure is 0.9 instead of the normal 1.1...so i went back to the place i bought my rad and asked for a 1.1 that fits my rad but they don't have it...what's up with that?!

do certain radiator brands fit certain rad caps?

tia