I bought a short block from a reputable shop in town. He was building for his own truck but changed direction. 5.3 out of a 07 suburban. Had all machine work done just needed cam and heads installed. Dod deleted with towers plugged and oil pan without a pressure relief. When installing the cam it was snugg on a couple spots. I had to kind of bump it with my hand to get it in. It was very tight and could not spin it until I put sprocket on. This is only my second build and a friend said that wasn't uncommon so against my better judgment I continued. Now that its in vehicle it was 65lbs on start up and once warmed up it idles at 16 to 22. Confirmed with mechanical Guage. Pressure shoots right up when throttle is pushed. I feel it is likely cam bearing issue but would like feedback. I did put new oem oil pump with red oring and know it was in correctly. New oil galley plug and cam plate also.

 

there was a lot of grey in the oil pan after oil change also

 

Camshaft should never have to be turned with sprocket or wrench. It should turn freely with just your fingers by the dowel on the front. Bearings were either mis-aligned or put in wrong spots. They all 5 have same inner ID dimensions, but there are 3 different OD dimensions per set of bearings. There are also different sizes for Gen3 and Gen4…not a one size cam bearing fits all, type of deal, if you follow me.
Cam bearing installation is an art. Anyone can buy the tool, but getting it right and having the camshaft turn smoothly without dragging usually takes a couple tries on at least one bearing. You can “feel” which bearing has an issue while carefully installing a camshaft, and taking time to stop at each bearing and spinning the camshaft. Again, there should be zero binding. If you went ahead and buttoned the engine up with the camshaft not wanting to turn very easily, it had to clearance itself, and hopefully it hasn’t “picked up” a cam bearing and spun one or two. If you saw grey matter in the oil, I strongly advise you cut the filter open and inspect the media. It will tell the tale on bearing condition. Use the proper oil filter cutting tool. Don’t saw it open.

 

Unfortunately, likely cam bearing(s) damaged. Pull pan and look up to see which bearings walked or show signs of distress. You can block off rear oil galley hole to filter and pressurize rear galley port (M16x1.5) with oil to see where it's bleeding.

 

if bearings are damaged, which that is my assumption, probably pulling the motor and replacing bearings is about my only option I guess.

 

Personally, I don't like to assume anything. Better to test/measure to better understand/know. If pan is easy to pull, I'd go for it. If not, yank motor then pan to inspect.