The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - when did GM put catalytic converters on Sierra 305s?

Greenlee · 01-06-2011, 06:00 PM

Is the truck a Big 10 or Heavy Half? My 76' didn't have cats because it was a Big 10. The whole reason behind the Big 10's and Heavy Half's was to get around emissions standards as I understand it.

01-06-2011, 06:00 PM	#7
Greenlee Registered User Join Date: Jun 2004 Location: El Lago, TX Posts: 1,668	Re: when did GM put catalytic converters on Sierra 305s? Is the truck a Big 10 or Heavy Half? My 76' didn't have cats because it was a Big 10. The whole reason behind the Big 10's and Heavy Half's was to get around emissions standards as I understand it.