How do I shop for the motor that is not original

[cowlby]

I have a 72gmc 1500 sierra that has a rebuilt 350 out of 78 blazer.

Engine details I know:

A 350 out of a 78 blazer is what I was told.
He added an HEI ignition, RV cam , A carter AFB, a holley performance intake, and later I added some headers to his rebuild.

I want to replace the spark plugs and ignition wires and possibly the hei distributor and coil cap.

My Question: When shopping for these items do I specify my vehicle as the 78 blazer (and guess at the model some sites ask for) or a 72 gmc sierra?

Thanks for any shared knowledge.