Putting a 454 through emissions

[COCHEV]

So I have the opportunity to buy back my old 454 for use in my 85 burb. It has 049 heads and a nice torquey cam but stock converted friendly, edelbrock mani with a q jet.

I talked to the DEQ and they don't care if it has a 350 or 454 as both engines have the same emissions requirements. Tail pipe test only. And my year and gvw didn't have a cat.

I know this is pretty hypothetical, but would I have to return to a mostly stock cam to get it to pass? I don't want to do all the work for the swap only to have it fail miserably. Mileage can't get any worse so I'd really like to have it back. Thoughts....

 

[paratrooper307]

Odds are any cam that is not close to stock is probably going to hamper your ability to pass an emissions test. While your vehicle doesn't require it, there's nothing to stop you from slapping a high-flow cat on there to hedge your bets.

 

[chulisohombre]

A high flow cat would help emissions a ton if yours wasn't equipped stock. The higher no2 and co2 would be blocked somewhat and unburnt gas from a Lopez cam would be burnt off as well. It would at least give you a better chance at passing. Can you test it in the vehicle it's in to see how bad it is before you swap it?

 

[FAB454]

Never had to do testing, so this may not even be possible. Has anyone ever just added multiple "smog pumps" to "lean out" the tail pipe?

 

[1BEATK5]

Never had to do testing, so this may not even be possible. Has anyone ever just added multiple "smog pumps" to "lean out" the tail pipe?

You can to a point, then it will fail for diluted sample. Not enough exhaust, too much air.