FWIW ;
It's really very simple as long as you're not too lazy ~
My old '76
GMC 2500 Long Bed Fleetside's 292 burned oil like crazy but didn't smoke much thanx to original HEI and careful tuning , '76 is the last year Cali. smogs so I went to work and replaced about 40' of various size hoses , added spring typ clips to every hose connection , timed it bang on , opened the spark plugs up to .070" and it
breezed through the smog test ! I forget the limits but the Tester told me he was amazed it ran so clean for such and old truck .
No CAT either
.
Long live dependable
GMC light duty trucks ! .
The message here is : if you take the time to dot every 'I' and cross every 'T' , it'll prolly be fine .
I had much fun (NOT !) hooking up the dual tanks various venting and vapor recovery hoses but the original 1976 activated charcoal canister still worked just fine .