help

[1977 chevy]

can anyone help me with my 1977 chevy stepside it was bout in 77 from show room the strange thing is it duz not have a EGR valve or cats on the duel exsosts is that normal for that year and if so what type of stuff can i put in the 350 to amp up the power but still be able to pas smog it always past smog sense 77 

[VileZambonie]

Good thing spelling doesn't count!  First off where do you live? Every state has their own emissions laws. If the vehicle came from the factory without EGR and catalytic converters then you would not need them. However if it's just a regular 1/2 ton it probably came through with single exhaust, catalytic converter, and EGR.

If you are worried about passing emissions then I would focus on that first before you start trying to squeeze more power from the engine.

[1977 chevy]

im from California , sorry about the selling    my 1977 was bot from the show room and it already had 2 tail pipes but no cats  and no egr valve it duz have a smog pump its a 1977 Chevy silverado  stepside with a 350 -4-barrel carb , power windows , tilt , and so on   . it is a half ton   

[VileZambonie]

Ok well you must be mistaken then because an A.I.R. Pump won't do you much good without a catalytic converter to benefit from the extra oxygen allowing it to oxidize. Under the hood there is a label called the VECI label. Vehicle Emission Control Information and I would see if you can locate it. It would say CATALYST if it came so equipped. The vacuum diagram would also depict whether or not it had EGR.

AS far as dual tails I don't think that in 77 true duals were available. According to my exhaust booke there was a dual split tail pipe though....