HelloCustomer here are the instructions but it does not include exactly where the intake or exhaust rods go. I've done a number but I never memorize which one goes where. I will tell you that the exhausts rods are longer. If I ever lose my way or don't put them in order I just look at where they line up; for example I look at the valve and rocker arm that the pushrod I'm installing is lined up with and see if it is lined up with the exhaust or intake, from there I believe they alternate but you can easily do this with each one as well. Anyhow I hope I didn't lose you there, please reply with any extra questions regarding this procedure you may have and here are the instruction, thanks:

Valve Rocker Arm and Push Rod Installation

Tools Required

J 36660-A Torque Angle Meter

Important: All gasket mating surfaces must be free of oil and foreign material. Use GM P/N 12346139 (Canadian P/N 10953463) or equivalent to clean surfaces.

Important: Do Not apply RTV sealer to the engine block before/prior to the installation of the manifold gaskets. RTV sealer is not to be placed under the lower intake manifold gaskets.

1. Install the lower intake manifold gaskets.
   
   
   
2. Coat the ends of the push rods using prelube GM P/N(NNN) NNN-NNNN (Canadian P/N 992869) or the equivalent.

   Important: 1995 and earlier engines use hardened pushrods and steel pushrod guide plates. For service of 1995 and earlier engines, only intake pushrods with purple markings and exhaust pushrods with orange markings can be used. Failure to do so may result in engine damage.

   Intake pushrods from 1996 and newer engines have either yellow or purple markings. Exhaust pushrods from 1996 and newer engines have either green or orange markings.

    

    

   All intake pushrods measure 144.18 mm (5.68 in) long, and all exhaust pushrods measure 152.51 mm (6.0 in) long.

    

    

3. Install the push rods in their original location.
   
   
   
4. Coat the rocker arm friction surfaces using prelube GM P/N(NNN) NNN-NNNN (Canadian P/N 992869) or the equivalent.

   Important: Shims may be required under the valve rocker arm pedestals if reconditioning has been performed on the cylinder head or its components.

5. Install the valve rocker arms in their original positions.

   Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

   Important: Thoroughly clean the fastener and tapped hole prior to installation.

6. Install the valve rocker arm bolts.

   Tighten
   Use the J 36660-A to tighten the valve rocker arm bolts to 42 N·m (31 lb ft).

HelloCustomer do you have the lower intake off at this moment like this picture:

If you do then if you look carefully into the intake passageway that goes into the head, you will see a valve; if you can see that when the valve opens it allows air from the intake in, it is an intake valve and follow it up to the top of the head and you will know you have to use a shorter pushrod there: Please reply if you still have questions, thanks.