I have heard that a b series radiator hose will solve the issue of fitment I am having with the lower hose on an aftermarket radiator. My question is off what model car the del sol or 2000 civic si etc?

 

What is the part number of the Mishimoto Radiator that you bought ?

 

MMRAD-CIV-92X
x line radiator

 

Are you suggesting that the radiator necks are LARGER in diameter than the upper and lower radiator necks on your D16 engine ? If they are, you have the wrong radiator. The larger "B" series necks, like those found on the '99-00 Civic Si or the '94-97 Del Sol DOHC, use a hose that is 1/8" larger inside than the SOHC Civics. If you try to use the larger hoses that fit the DOHC radiator, they will likely leak when you try to "pinch" them down to get them snug on your engine.