1971 C20 custom camper longhorn had original dual exhaust?

[dads longhorn]

Hi experts. I was wondering if the truck mentioned had dual exhaust as original equipment, or did it originally have a "y" pipe joining the mid pipes into one tail pipe. Now, the truck has dual pipes all the way from the exhaust manifold to the tail pipes, (2 mufflers). The exhaust guy on the phone was suprised by that, and said the truck originally had only one tail pipe w/ a "Y" junction.

2nd question. I have a leak rusted through the exhaust pipe and need to get it fixed. Does the pipe have to be replaced, or can they patch the hole in the pipe? I don't recall if the hole is before or after the mufflers.

Lastly, the last exhaust guy (who replaced the cracked exhaust manifold and replaced mufflers) said because the truck was meant to carry/ pull heavy loads, that the diameter of the exhaust pipe should be bigger than what he saw on their now. So, what diameter was the original exhaust pipes? Should I get a biggher diameter (But I have no plans to put a camper on the back...yet).

Thanks for your help, in New mexico

[JimKshortstep4x4]

If the truck had dual exhaust on it from the factory there will be two sets of hangers on the frame. Look for a hanger that is riveted to the frame which supports the muffler on the left side. If the truck had duals originally there will be a hanger just like the one on the left that is riveted to the right frame rail straight across from the left side.

I believe the big blocks had 2 1/2" pipes on both sides, front to rear.

Jim

[70cst]

I think...only BB trucks came with factory Dual exhausts. I might be wrong. JFYI

[special-K]

Yes,"any" 10-30 truck equipped with a big block had dual exhaust. There will be frame brackets and heat shields for both sides. No small block equipped trucks came with dual exhaust.

[RenoKeene]

I concur with Tim, my factory BB had 2-1/2" duals and my SB Custom Camper had single exhausts.

[dads longhorn]

Thanks for the great input folks. Is a 350 V8 a big block? Yes, I know nothing about this truck and am still in the process of learning, it's ok to chuckle at me. The weather hasn't cooperated lately and i haven't been able to crawl under the truck to look for brackets holding the exhaust or heat shields (where are theHS located). The engine was rebuilt/replaced and the numbers on the block are V0319TYZ, so it's a 1975 (not 1971 like the rest of the truck), 350. I know it's still a V8 though.

Can the hole in the pipe be plugged or should i get new pipes put on. I'm thinking new pipes since the current ones will probable rust out again in the near future and makes a bad noise (i like the sound of the mufflers now).

Thanks again

[litew8]

No, a 350 V8 is not a big block. Replacing the [rusted] pipe(s) would be best.

[VWBeamer]

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.

[dads longhorn]

Thanks guys, I got it now!

litew8, i see you are from Iowa. THANK YOU and to all Iowans! I passed thru your state for the first time in 2010 on RAGBRAI and the people of iowa were very nice, generous, down to earth, and kind to the riders. I thank you and all iowans for your support of RAGBRAI.

[litew8]

You're welcome and thank you. I actually use to work for the newspaper that sponsors RAGBRAI.