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stangs-R-me

New '68-69 Rolled Lip Exhaust Tips with 2.5" Inlet

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Bought a pair of these custom 2-1/2" Inlet Tips a few months ago from CJP and was just blown away with how they opened them up inside for maximum flow.

Twin tips are externally the same, rolled edge is a little tighter though giving a bit more opening: Stock approx. 1.50" x 2.14" vs. 1.65" x 2.33" oval area each tip.

My exhaust is stock late 80's repro (transverse muffler) but the larger 2-1/4" 428 version instead of the 2" that should be behind a 351W.   In order to fit the stock tips on the tails that came in this exhaust system I had to shorten them a bit as well as reduce the end dia. to slip into the tiny 1-3/4" inlets on the stock tips … in hindsight, I'm guessing tails were for GT500.   This always bugged me but assumed at the time that the tips were the same for all engines so this is how it would have been on a Big Block.     

Come to find out more recently that 428 Mach 1's & GT's with this 2-1/4" exhaust came with special tails with less restrictive tips welded on the tails instead of the separate tips used on 390 & 351's.   These unique tails are now being reproduced by Scott Fuller … but for the concourse crowd … so not cheap.

So, since I had already cut & re-welded my tails to fit the stock tips way back when, I just ordered (2) 2-1/4" ID x 2-1/2" OD x 6" long aluminized 16Ga. adapters.   I'll cut forward of my current welds and slip these adapters on, adjust to desired length, then weld these new adapters on.   Stock tails are 16Ga. aluminized steel too, so I was happy to find these adapters made out of the same gauge tube.

Scott Drake makes similar tips for 2-1/4" tails that sell for quite a bit less than these 2-1/2" versions, but from the inlets back look to be similarly restrictive as the stock ones so not worth the cost & effort for minimal improvement.

Both tails slipped out of the muffler without any issues, so I'm just waiting for the adapters & 2.5" clamps to arrive from Summit next week.

Doug     

Stk vs Big Ex-Tip 1.JPG

Stk vs Big Ex-Tip 2.JPG

Stk vs Big Ex-Tip 3.JPG

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CJ's Part Number for the 2-1/2" Tips is: EXT25  … currently $174.99 / pair and in stock in PA

Have no idea who makes them, boxes had no name or p/n other than CJP's number.

 

For comparison, pic below is the Scott Drake ones for 2-1/4" which CJP sells for $95.36 / pair.   The 2-1/4" inlet is a huge upgrade from 1-3/4" but they step down twice to the same 2nd choke point where it is welded to what appears to be the OE style twin tip junction.  No internal shot, so don't know if the divider flap of metal (that is completely removed from the 2-1/2" design) is in there or not.

1109354119_SDC7ZZ-5258-GT2.thumb.jpg.706a464cab107e73d78517dc68519b28.jpg  

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Got the parts earlier this week and finished up the project today … turned out really nice with no clearance issues anywhere.

Was thinking the rolled lips were going to still be the smallest restriction, but with a little math I found this is NOT TRUE … the 2-1/4" exhaust system tubing I.D. is actually less area than the twin tips.

2-1/4" 0.065" Wall Tubing = 3.528 sq-in area each

Twin Tips are 1.895" I.D. = 2.82 sq-in area each x 2 = 5.64

Rolled Slant Cut Oval = 3.019 sq-in area each x 2 =6.038

The 1-3/4" O.D. crimped down tail ends I had before with the OE style tips = 1.986 sq-in area

vs. the 3.528 sq-in of 2-1/4" tubing is a 77.6% increase in area which is a huge improvement.

Using these tips on a 2-1/2" System would not be a restriction either as this with 0.065" Wall tubing would be 4.41 sq-in area which is also smaller than the twin tips.

 

Stk vs 2.5IN Tail&Tip 2.JPG

LH 2.25IN Tail & 2.5IN Tip 1.JPG

LH 2.25IN Tail & 2.5IN Tip 3.JPG

RH 2.25IN Tail & 2.5IN Tip 2.JPG

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12 hours ago, Machspeed said:

Those look really good! Was hoping they would also produce a 70 version but unless I missed them, don't see them.b Thanks for sharing

Hey at least the OE '70 Mach 1 Tips came with a 2-1/8" Inlet and the Scott drake Concourse repro's claim they will fit up to 2-1/4".   Interestingly, the Scott Drake tips are Chrome Plated Steel and not 304 stainless like the '67-69 tips.   Read a few complaints about the SD tips rusting through the chrome quickly too, so that's not good.  

There are stock looking Rolled-Lip '70 Tips on ebay made out of 304 SS that would be the way I'd go if I had a '70.   Sure they would also fit 2-1/4" and maybe could be even be expanded by an exhaust shop to fit 2-1/2".

Doug

      

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1 hour ago, stangs-R-me said:

Hey at least the OE '70 Mach 1 Tips came with a 2-1/8" Inlet and the Scott drake Concourse repro's claim they will fit up to 2-1/4".   Interestingly, the Scott Drake tips are Chrome Plated Steel and not 304 stainless like the '67-69 tips.   Read a few complaints about the SD tips rusting through the chrome quickly too, so that's not good.  

There are stock looking Rolled-Lip '70 Tips on ebay made out of 304 SS that would be the way I'd go if I had a '70.   Sure they would also fit 2-1/4" and maybe could be even be expanded by an exhaust shop to fit 2-1/2".

Doug

      

Yes, I have a set that I purchased off ebay a few years ago. In fact, I posted about them here and a few members also purchased them. They were very reasonable in price and appear to be high quality stainless. I think they are 2-2 1/4. Regardless, they will require an adapter for my exhaust. 

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