1953 Chevy 3100, 235 engine with Fenton Headers. Just mocked up my exhaust and it looks to be hanging too low or too close to the ground. The muffler is about 6 inches lower than the stock muffler location. Is it normal for exhaust systems to hang lower when using the fenton headers? Should I try to raise it up some? I put a level on the muffler and rear tailpipes and they are sitting level and exit under the bumper. They are about 6 inches lower than the bumper. None of the bolts are tightened yet, so there should be some adjustment that I can make. Looking for what's right under these circumstances.
It needs to be low enough to clear the bell housing, clutch, and brake master cylinder comfortably. Mine is higher than my running boards. They are the lowest part of my truck. My truck is standard height as it came out from the factory.
There is such a thing as the “scrub line” , if I remember the term correctly. I don’t recall the pure definition, but basically it refers to the fact that vulnerable components need to be above structural elements of the truck , I. e. the frame, to prevent them from getting damaged or scrubbed off if the vehicle bottoms out. This particularly applies to front end components, the loss of which could be disastrous.
I don’t know if the scrub line standard applies to exhaust components, but it does sound as though you need to assess how exposed your exhaust system is to grounding damage.
That and I also think that the exhaust pipes are too close to the rear axle. I think the axle could impact the pipes if I hit a good bump. I'm going to try and adjust the pipes and muffler tomorrow and see if I can get it to sit higher up. I just don't know where the normal exhaust system sits in relation to the ground and underside of the truck. A pic or two of what's normal would be worth a thousand words....
Made some progress on the exhaust height today. I loosened up all of the connections and used the floor jack to raise things up as far as I was comfortable doing. I got another 2 inches of height on the system. The muffler is now 4 inches lower than the stock muffler bracket. The pipes are 10+ inches off of the garage floor. Where the pipes cross over the rear axle now has lots of room. The pipes are higher than the bottom of the differential cover, but lower than the running boards. Everything nicely clears the engine/transmission. The pipes exit under the rear bumper, but are now only 1.5 inches under the bumper. I may look for a short turn down pipe to direct the exhaust towards the ground. Pic attached of the muffler and rear pipes. They are currently covered in plastic to protect them from the rear cab corner replacement crud that I'll make while working....
Here are a few views of my exhaust. There is nothing stock in this exhaust system, it is a 283 exhaling through headers. My mufflers are a wee bit below the scrub line; ground clearance is reasonable. I didn’t think to measure that clearance.
