i have a 90 k5 that is passenger dropMany people run an NP231/241 INTO a D300 without any ill affects. Also many people feed a 4:1 Klune into a D300. If your concerned you could swap to front and rear HD outputs on the D300 in time (suggested). What year is your Blazer? Driver drop or pass.? I am assuming it is an earlier Blazer with pass. drop.