Hy 91000, Welcome, your truck is a Canadian GMC with a GVW of 25000 Lbs., it is powered by a Chevrolet 348 cu. in. V8 engine. Those trucks were available in five different wheelbases, if you post the trucks serial number I will decipher it further. I suspect your truck is a former fire truck judging by the twin spot lights and stainless trim. As to parts availability, the 1 1/2" bore master cylinder has been unavailable for many years, but it can be resleaved if necessary. The wheel cylinders should still be available, as will the flexible brake hoses. You should start your own topic on your truck, tagging onto this other post kind of hides you
