The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 1971 C20 custom camper longhorn had original dual exhaust?

VWBeamer · 01-17-2012, 12:58 AM

The 350 is a small block. The 396, 402, 427 and 454 are big blocks. They also made a 400 small block just to confuse us. Any V-8 350 or smaller is a small block.

If you are planning on keeping the truck I would replace the pipes completely with 2 1/2 inch pipe. The cost to do so is not much more and the larger pipes will give you a small HP increase and a small MPG increase. the larger pipe also sound better IMHO, not sure why.

I feel if you patch the pipe you will be addressing the problem again in a year or so.

01-17-2012, 12:58 AM	#8
VWBeamer Registered User Join Date: Jun 2011 Location: GA Posts: 281	Re: 1971 C20 custom camper longhorn had original dual exhaust? The 350 is a small block. The 396, 402, 427 and 454 are big blocks. They also made a 400 small block just to confuse us. Any V-8 350 or smaller is a small block. If you are planning on keeping the truck I would replace the pipes completely with 2 1/2 inch pipe. The cost to do so is not much more and the larger pipes will give you a small HP increase and a small MPG increase. the larger pipe also sound better IMHO, not sure why. I feel if you patch the pipe you will be addressing the problem again in a year or so.