im gettting a 1986 k20 its got a 454 the story behind it is it was orginally a 292 6 cylinder could you have ordered a 1980 454 for a k30 in 1986 also was told 1980 was ordered because it didnt have smog equipment

 

Of course you could...just ask a good parts guy in a GM dealership. If you live in an emissions compliant area I would think you will be unable to go thru inspection without emissions eq.. Just a thought

 

1978 was last year with NO Catalytic converter (1977 in California) in <1/2 tons and all 1979 models, except for C/K 30/35 vehicles, had cats.

For 1979 on, the dividing line between light and heavy duty emissions was raised from 6,000 lbs GVWR to 8,500 lbs GVWR, forcing more trucks to comply with the stricter emissions standards than previously. 1980-1986, the same models as those for <79 used cats. However, a new C6P Heavy Duty option was offered for C/K 20/25 models which provided an 8,600 lb suspension package. These new, heavier 3/4 tons cleared the 8,500 lb limit, and so did not use converters during this time period, nor did C/K 30/35's.

Also, your truck is a 1986, it has to follow equipment for 1986, no matter what year engine you install. Is yours the Heavy Duty with 8,600 lb suspension package?

Locate both the engine and date code on the top driver's side of the bell housing flange, that will tell you what year it was manufactured.

If they still had 1980 454 available, yes they could have been ordered.