Hello...Just obtained my first military rig...I recovered a 1970 kaiser m818 w/winch with a 1970 nhc 250 cummins power plant from the lower part of ohio...Truck was only reading 1277 miles when I picked her up...Checked all fluids and headed for home about 300 miles away. 5 hrs and some change later I rolled into home base...What a ride! On arrival i did a post trip inspection and noticed that I had developed an external coolant leak on the rear head... Truck never over heated ran a steady 175 to 180 degrees with an 80 degree outside temp...Dipped a rag into the surge tank and found that the coolant was brown and smelled of diesel and had a slick film on top of the coolant... Drained all the old coolant and started into my disassembly. Luckily I was able to track down a upper end gasket kit for a very reasonable price from a local cummins dealer...Everything came apart smoothly and with much of the very useful information I have found on this site aided me in my teardown...I made the decision to replace all injectors while i had the top end torn down to this point. I have tried searching the site but couldn't find an answer i was looking for...Is it possible to use newer top stop style injectors in my engine if it originally had the non top stop style injectors? I ordered non top stop but received top stops this is why I ask...The business end of the injector all lines up but the top end of it,where the jam nut is located, is a much different dimension... It is Much taller than the non top stop...I would like to thank everyone who is a part of this site for all the time and info they have put forth to make this such a useful website...Thanks again.