“Correct” Exhaust to rear Valance Fit?

Hello:

My 73 Grande has dual 2 1/2” exhaust, coming through the rear valance. My exterior look question is, what is the “Correct” length and angle of cut? I don’t think these ever came with dual exhaust, so I don’t think there is a factory answer, but what about 71/72’s and their dimensions? Thank you in advance.

You should have 3/8" all around the exhaust tip to the valance panel. This centers the pipe in the cutout. The amount of "stick out" of the tips was set by the exhaust system itself. I'd say about an inch would look right. Don't be one of those guys that has them out so far you could trip over them.

On 1966 Mustang GT's, the exhaust tips were roughly equal in extension with the rearmost part of the bumper.

Would you cut the pipe at an angle, parallel to the valance?

Mustangs with the rear valance "cut outs" used chrome extension tips connected to the tail pipes. The tail pipes were recessed far enough back for the chrome extensions to be positioned correctly. Here are a couple photos of what that looks like. The one shown is NOS. Repros are available.

I ended up having to recenter one of the pipe tips. In the video in the link below I extended the tips from their position when I purchased the 73 Mach 1. I eyeballed the amount the tips stuck out. Turned out nice.

Doug, do those fit over a 2 1/2” pipe? mrgmhale, how far from the edge of the valance output does that pipe extend?

Steve McMahan said:

Would you cut the pipe at an angle, parallel to the valance?

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That is what I did- but I am not trying to keep my car 100% correct.

Steve, they fit on 2 1/4" tail pipes reduced to 2 1/8" at the end where the extensions attach. The extensions are 3" OD where they pass through the valence cutout notches.

Steve McMahan said:

Doug, do those fit over a 2 1/2” pipe? mrgmhale, how far from the edge of the valance output does that pipe extend?

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I bought my tips from Stainless Works they offer the slant cut tip in multiple inlet and outlet sizes. They are a bit pricey but I was impressed by the quality. I ordered mine with the 2 1/2" inlet to match my exhaust and a 3" outlet. They are a little larger than the stock tips, the reproduction tips have a 2 1/4" inlet, but I like the look. They also have a sort of resonator in them, you can see in the third picture, that I didn't notice until after they were installed.

Bentworker, what are the dimensions and angle of that cut? I like that look.

I’m thinking, I can cut the down angle now, and if later I want to add the chrome end, I’ll still be able to do so. Right now, chrome tips would seem like earrings on a pig.

Steve McMahan said:

Doug, do those fit over a 2 1/2” pipe? mrgmhale, how far from the edge of the valance output does that pipe extend?

Click to expand...

I will measure at the top of the tailpipes and let you know what that length is. I will be doing a lot of work on the 73 Mustangs today, so it may be a whilee before I am back on the laptop and handling emails, etc.

Steve McMahan said:

Bentworker, what are the dimensions and angle of that cut? I like that look.

I’m thinking, I can cut tje down angle now, and if later I want to add the chrome end, I’ll still be able to do so. Right now, chrome tips would seem like earrings on a pig.

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I don’t have a protractor handy but the angle matches the rear valance. I had the same idea that tips could be added later.

Just measuring using a printed copy of the photo, looks like 60 to 62 degrees

Steve McMahan said:

Doug, do those fit over a 2 1/2” pipe? mrgmhale, how far from the edge of the valance output does that pipe extend?

Click to expand...

Hi Steve!

I measured along the top of the two chrome outlets to the end of the tip. They extend 4 1/2" out of the valance (at the top of thee pipe, just to re-clarify). When I stand directly above the rear bumper the tips are tucked in about 3/8" visually, so they to not go past the rear of the back bumper. I have not ever looked at them and wondered if they would look better going wither inward or outward from their current position.

I did install an x-pipe a little while later, and adjusted the right exhaust pipe so the tailpipe extension is more centered in the valance cutout (in the video it was further from the left edge of the valance cutout than the right edge. It looks far better balanced now, but nobody ever said anything about the imbalanced outlet through the valance cutout before. It was just a minor pet peeve of mine.

The entire reason for me extending the outlets was to stop the carbon splatter at initial startup from getting all over the valance. The extended exhaust tips did the job perfectly, and added some style visually at the same time. Well worth the effort, and small an effort it was.

The tips look great -

quick question, my lower bumper valance doesn't have exhaust cut outs like those in the pics in this thread. Is there a version with and without or perhaps mine was replaced with prior owner? I'm thinking at this just to have rear pipe bent down to let the tips go below my valance.

GrantOv said:

The tips look great -

quick question, my lower bumper valance doesn't have exhaust cut outs like those in the pics in this thread. Is there a version with and without or perhaps mine was replaced with prior owner? I'm thinking at this just to have rear pipe bent down to let the tips go below my valance.

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There is a unique Mach 1 rear valance for the dual exhaust tips. Only Mach 1s that were originally equipped with 351C 4V (M, Q, or R-code) or, in 71, 429 engines came from the factory with this valance. Retrofitting the valance and dual exhaust tips is pretty straight forward, though will cost a few bucks for paint work and tailpipes, if needed.