if you mean valve clearance its .26mm intake side and .30mm exhaust side
intake 0.05mm-0.09mm (0.002"-0.004") exhaust 0.11mm-0.15mm (0.004"-0.006")
do you mean the EGR valve? it's at the base of the intake manifold
Real simple exhaust camshafts are the camshafts nearest the exhaust manifolds ( outside if cylinder heads) intake camshafts are on the inside closer to center of engine.
top of intake behind fuel rail
EGR valve is allways connected to the exhaust pipe. It goes to the intake. It allows exhaust to flow into intake to reduce N.O. It has a vaccuum hose connected to it. The hose may be connected to a solenoid. On 94 and up check for ohms, if open replace. If this solenoid is bad you will fail smog every time. EGR valve is bolted to the manifold on passenger side, just underneath the carburetor. There are three hex head screws, requires 10mm socket.
It is on the back left side of the intake, just above the valve cover.
its located on the intake manifold close to where it connects to head There's another PCV located under that.
A 1989-1993 Cummins has 160 HP stock, The 94 and 95 automatic also had 160 HP, The manual in 94 and 95 had 175 HP, a 95 High output was 180 HP. In 96-98 the auto was 175 HP and the manual was 215 HP. 1998 was the last year of the 12 Valve Cummins. An intake and a 4" exaust should add 20-30 HP and a 2-3 MPG increase on your truck.
The pcv valve on my 94 1.0L is located on the intake manifold, top, center, close to the block. for later models however it is in a hose between the valve cover and the intake manifold; in an 11 o'clock direction from the oil filler cap and in front of the air filter housing
The EGR is located on the back of the intake manifold, check out www.shbox.com they'll have most of your answers.
Under hood, center, upper engine area, front of carburetor, mounted in intake manifold