new to this. excuse me. I need a emmissions diagram for a GM remanufactured 454 7.4L HD with EGR Please!?

Question

I HAVE A 1980 GMC SEIRRA C2500 3/4 TON TRUCK WITH 2 WHEEL DRIVE THE ENGINE HAS BEEN REPLACED.
CURRENT MOTOR IS A GM REMANUFACTORURED 454CID 7.4 LITER , (NOT SURE ABOUT THE LITERS), HEAVY DUTY WITH EGR VALVE. CAN'T, LOCATE ENGINE MARKINGS?
WENT TO SMOG, AND THEY INFORMED ME THAT THEY COULD NOT FIND THE EMMISSIONS DIAGRAM FOR A 454CID HD ENGINE WITH A EGR VALVE. CAN NOT SMOG UNTIL I FIND THE DIAGRAM. I AM A CAREGIVER AND THE INCONVIENENCE OF NOT HAVING MY TRUCK TO DRIVE IS ADVERSELY EFFECTING MY CLIENT. PLEASE, ENLIGHTEN ME!!!
HOW , CAN I CORRECTLY IDENTIFY MY ENGINE SIZE. AND, WHERE I CAN GET THE EMMISSIONS DIAGRAM.
ANY IMPUT ON THIS MATTER WOULD BE HIGHLY APPRECIATED. THE VIN ON THE TRUCK IS:
TCM24AJ506599 YES THAT IS ALL OF THE VIN APPARENTLY, PRE-1980 VECHILES HAD FEWER NUMBERS

Answer 1

7.4L is correct. Couldn't tell you where to find emission diagram. Do you need it for the test? They are seeing what is coming out of the pipe, not how it got there.

Answer 2

Don't ya just hate it when you get hung out like this???
There are several places to locate the diagram.
On the 1980 year, there SHOULD have been a vacuum routing map either on the radiator support/fan shroud, or on the air cleaner housing or lid. It is what THAT PARTICULAR vehicle was equipped with, and is required to conform to. If it is missing for whatever reason, the next step is...
1) Locate a repair manual for the vehicle, and follow what is there.
If that is unavailable,
2) Go (don't call, it only annoys them) to the dealer service department, and ASK for a photocopy of the routing for the vehicle, and be certain to get the correct map, regarding certification (Federal or California).
or
3) The local library has a set of auto repair references, including either MITCHEL or MOTOR vacuum routing manual, which should cover nearly everything from about 1966 to present. You should be able to locate what you need there. Again, be certain that you get the correct certification, as the equipment varies, and thus so will the routing.
Failing all of this, if your state requires the emissions test, they should also have an arbitration process which may include an equipment referee. If so, you should make a appointment with that agency or provider and ask for the information from them. In California, we have such a recourse, and they can provide the necessary information.
For that matter, the Licensed Smog Test and Repair centers are required to have the information on hand (otherwise, how would they know what is correct and which has been modified if the factory label is missing?) and shouldn't charge you unnecessarily to check and correct the necessary plumbing to conform to the requirements to pass the test.
It may cost a little (after all, they are a for-profit enterprise, and must pay the overhead and help) but it shouldn't be prohibitive.
If it is beyond your means, there is a mechanism for the state to subsidize the cost to some degree ir the shop is unwilling to help out a little.

Good Luck