Is it possible to........ - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mexgrhd68 · 12-23-2008, 08:03 PM

with the smog laws here in cali, is it possible to swap a 350 instead of the stock 305 my 79 gmc came with. I hear that if truck came with 305 you have to leave the 305 in it because its registered with the 305, is this true?

gchemist · 12-23-2008, 08:37 PM

If put a 305 and 350 next to each other you can't tell them apart. You would have to look very carefully. You can swap engines but the 350 will have to meet the emission standards of a 350. Check with your state inspection agency.

68c10owner · 12-24-2008, 12:51 AM

I`m doing that with my 84. 350` s were available in these trucks so it`s considered a replacement engine according to my buddy who is a smog guy. Also as stated above, they look the same so don`t tell them it`s a 350 and see what happens. I`m building my 350 to be smog legal so we`ll see what happens next time I need to smog it.

piecesparts · 12-24-2008, 02:23 PM

You guys in Calif. can keep the smoggies out there. thank God, I don't have that problem.

chevyrestoguy · 12-24-2008, 09:26 PM

Once it's in the truck, you'll be hard pressed to tell the difference between a 305 and a 350. I haven't met a smog tech yet that will run the numbers on the motor to tell what the cubic inches is. Go for it. Just paint it the same color as the old 305. The amount of difference in emissions between a 305 and a 350 is almost nil.

ChaseDale3and8 · 12-24-2008, 09:44 PM

Quote:

Originally Posted by piecesparts

You guys in Calif. can keep the smoggies out there. thank God, I don't have that problem.

Amen brother! California does have the strictest smog laws! I read somewhere that as long as that the engine that is replacing what you have in it now is the same year or newer it won't be a problem.

As the others have stated, visually they look the same, and as long as you have all the smog crap that it came with hooked up and functioning properly, including the cat converter you should be fine. Before swapping out, I'd make damn sure that the 350 was in tip top shape if it wasn't a freshly rebuilt or crate engine, because that might end up being where things get sticky. ...Joe

12-23-2008, 08:03 PM	#1
mexgrhd68 Registered User Join Date: Apr 2007 Location: Visalia, CA. Posts: 327	Is it possible to........ with the smog laws here in cali, is it possible to swap a 350 instead of the stock 305 my 79 gmc came with. I hear that if truck came with 305 you have to leave the 305 in it because its registered with the 305, is this true? __________________ 68 c-10 1/2 ton swb fleetside, 79 GMC Sierra Grande 1/2 ton swb fleetside, 99 Dodge Durango 4x4(wifes ride),53 and 55 chevy trucks(dads trucks ) 54 caddy 62 series 4 door(younger sons ride, aka 54caddy ) 70 caddy 2 door, 89 chevy silverado stepside(older sons rides )

12-23-2008, 08:37 PM	#2
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Re: Is it possible to........ If put a 305 and 350 next to each other you can't tell them apart. You would have to look very carefully. You can swap engines but the 350 will have to meet the emission standards of a 350. Check with your state inspection agency. __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

12-24-2008, 12:51 AM	#3
68c10owner Registered User Join Date: Oct 2003 Location: Carmichael, California Posts: 3,011	Re: Is it possible to........ I`m doing that with my 84. 350` s were available in these trucks so it`s considered a replacement engine according to my buddy who is a smog guy. Also as stated above, they look the same so don`t tell them it`s a 350 and see what happens. I`m building my 350 to be smog legal so we`ll see what happens next time I need to smog it. __________________ Anthony

12-24-2008, 02:23 PM	#4
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: Is it possible to........ You guys in Calif. can keep the smoggies out there. thank God, I don't have that problem.

12-24-2008, 09:26 PM	#5
chevyrestoguy Registered User Join Date: Mar 2005 Location: apple valley, ca Posts: 2,670	Re: Is it possible to........ Once it's in the truck, you'll be hard pressed to tell the difference between a 305 and a 350. I haven't met a smog tech yet that will run the numbers on the motor to tell what the cubic inches is. Go for it. Just paint it the same color as the old 305. The amount of difference in emissions between a 305 and a 350 is almost nil.



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