Plate rib temp question

theeggcellentchef

Haven’t done these in a while so not sure. 

Is it normal for the meat temp on a plate rib rack to be at 155 3 hours in cooking at 275 dome temp?
Here’s what they look like. 

lkapigian

Sounds normal to me, rock them like a brisket, cook till probe tender 

dbCooper

I make these regularly but never measure the meat temp.  My cooks are at about 250 and go for 5-6 hours.  They are done when they "probe like butter".  I think you are fine with your progression.