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-   70-73 Firebird & TA TECH (https://forums.maxperformanceinc.com/forums/forumdisplay.php?f=437)
-   -   OE vs SR chrome tips (https://forums.maxperformanceinc.com/forums/showthread.php?t=866029)

unruhjonny 04-18-2023 08:34 PM

OE vs SR chrome tips
 
2 Attachment(s)
Has anyone noticed the differences between OE and SR exhaust tips?

Bottom to top these are:
- my car's original tips
- 71.5-73 OE tips (a set I laughably forgot I had)
- 71.5-73 OE tips (recently bought because they were in great shape)
- 70-73 SR tips

https://forums.maxperformanceinc.com...1&d=1681864053

Has anyone noticed that in addition to the part number being stamped on the top/rear edge of the service replacement parts, they differ from the OE 71.5-73 by:
1) being a couple inches longer
2) and have a narrowing at the bend.

The previously know difference is shown below:

https://forums.maxperformanceinc.com...1&d=1681864053

Granted, when the tip angle changed, it was the replacement part - and that should not be a surprise to anyone...

Yesterday when I put the SR tips near an OE set, the thing that immediately jumped out to me was the narrowing at the bend;
I intended to make a post about this, but then when I made the picture, I noticed the length difference too.

(IIRC the 74-75 tips are about a foot longer than the 70-73, and have another bend to tuck it under the bottom of the bumper cover... or something like that.)

Held for Ransom 04-18-2023 08:54 PM

Quote:

Originally Posted by unruhjonny (Post 6422040)
(IIRC the 74-75 tips are about a foot longer than the 70-73, and have another bend to tuck it under the bottom of the bumper cover... or something like that.)


More like 3".


Did you find a PN stamped where the exhaust pipe goes in?

keith k 04-18-2023 09:26 PM

Interesting comparisons. It looks like the original tips were bent with an internal mandrel, and the SRs weren't.

unruhjonny 04-19-2023 11:37 AM

Quote:

Originally Posted by Held for Ransom (Post 6422048)
More like 3".

Thank you for the correction, you made me look further into this, and it appears as though my memory was a bit fuzzy:

Quote:

Originally Posted by Rocky Rotella (Post 6202419)
While many companies market exhaust extensions common to '74-75, and the two years do share a similar appearance, the '75 extension is definitely different than the '74 unit.

The attached photo illustrates the differences between the two. In addition to the lateral bends (which creates specific LH and RH extensions), the '75 unit was welded to the tailpipe and sold as an assembly where the '74 unit was a slip fit design and sold individually and fit both sides.

The one-year-only '75 extensions are certainly rare. They were limited to 400-powered Trans Am (455 cars had splitters) and I believe the '75 Formulas were equipped with them as well.

https://forums.maxperformanceinc.com...7&d=1607091810

Quote:

Originally Posted by Held for Ransom (Post 6422048)
Did you find a PN stamped where the exhaust pipe goes in?

You made me look closer;
Bottom to top these are:
- my car's original tips: if there was a number it's gone, I used a grinder to clean the end of the one which still has the neck
- 71.5-73 OE tips: 481525S1W ("W" appears to be weakly stamped)
- 71.5-73 OE tips: (no numbers)
- 1974 SR tips: GM495832FT (not on the neck; added for clarity)

Please notice that I have corrected myself - I thought that these were in fact 70-73 SR parts because they were pulled off of a 1973 Formula 455(M40) the better part of twenty years ago.

When I read last night that the 1974 tips were only three inches longer, I wondered to myself if they were actually 1974 parts.

After looking for part stampings, I took it a step further and pulled out an MPC, looked up group 3.705 (mentioned in the thread where Rocky's reply was taken from) and found the following:
Quote:

2 - 481525 1970/8CYL - 4BC; 1971-73/ALL WITH FORMULA OR TRANS AM - DUAL EXHAUST
2 - 495832* 1974 DUAL EXHAUST
1 - 498164@ 1975/ALL WITH DUAL TAIL PIPES - RIGHT
1 - 498165@ 1975/ALL WITH DUAL TAIL PIPES - LEFT

* NEW PARTS REVISON #2
@NEW PARTS MASTER CAT.
(print date: November 1974)
Maybe some 70-73 cars appear to have longer tips because they are using the 1974 tips(?) - as this was the case with the 1973 Formula I pulled them from;
I wonder if the 1974 tips ever superseded the 70-73 tips?

Held for Ransom 04-19-2023 04:22 PM

2 Attachment(s)
I had thought when you first posted, you knew the '832 extensions were '74.

Pictured is the difference between the GM replacement 71-3 and 74 extensions.

https://forums.maxperformanceinc.com...1&d=1681935637

Picture of the stamped part numbers.

https://forums.maxperformanceinc.com...1&d=1681936845

And, a picture of where earlier ones may be stamped.

https://forums.maxperformanceinc.com...4&d=1288046787

redonred81 04-19-2023 07:54 PM

Tips
 
Btw who makes the best repro tips for 74?

unruhjonny 04-19-2023 09:05 PM

I think Ames offers them.

I bought a set (of the correct for 1970 tips) as soon as they were released (at the time it was 'Perfomance Years' that offered them - but Ames bought PY).
I believe they are now offered in stainless steel as well as chromed.

Ramairnacho 04-20-2023 03:37 PM

Tips
 
Quote:

Originally Posted by unruhjonny (Post 6422225)
I think Ames offers them.

I bought a set (of the correct for 1970 tips) as soon as they were released (at the time it was 'Perfomance Years' that offered them - but Ames bought PY).
I believe they are now offered in stainless steel as well as chromed.

I will need a set of chrome for my 1970 formula too
.can you post and compare the repops and give us a review? I hope they still available.

kingbuzzo 04-20-2023 04:26 PM

I just bot the Pype's equivalents for my '74 however I didn't have anything to compare them too and prior to yer detailed analysis!

https://www.pypesexhaust.com/product...-304-stainless

Anything will look better than the wrong tips the previous owner put on there...

unruhjonny 04-20-2023 06:39 PM

As it happens, I I actually looked up the repops last night;
The 70 / 71-73 & 74 tips are offered;
The 1975's application is to use the 1974 tips.

The repops I bought nearly twenty(!) years ago are actually NOT offered;
The repops offered are now only available in stainless steel.
(I bought original style chromed steel.)

I will add this (even though I've posted about it in the past) because it shouldn't hurt our host - since they are no longer offered as I bought them.
They were absolute dead ringers...
Unfortunately they didn't even last one summer before they started rusting.

I was pissed.

I looked at them the other day (I have my complete exhaust haning from the bottom of my garage trusses) - you would be hard pressed to notice that they were chromed... lol.

Formulabruce 04-21-2023 11:03 PM

Quote:

Originally Posted by unruhjonny (Post 6422421)
As it happens, I I actually looked up the repops last night;
The 70 / 71-73 & 74 tips are offered;
The 1975's application is to use the 1974 tips.

The repops I bought nearly twenty(!) years ago are actually NOT offered;
The repops offered are now only available in stainless steel.
(I bought original style chromed steel.)

I will add this (even though I've posted about it in the past) because it shouldn't hurt our host - since they are no longer offered as I bought them.
They were absolute dead ringers...
Unfortunately they didn't even last one summer before they started rusting.

I was pissed.

I looked at them the other day (I have my complete exhaust haning from the bottom of my garage trusses) - you would be hard pressed to notice that they were chromed... lol.

I had those 70 tips as well, and discussed the chrome on them with Steve at his place in Marlboro about 6 months after I got my set.( Circa 2001?) He was welcoming feedback and Mine was Not good. The chrome was Not triple plated , but the real problem was the pour off for the metal was impure and it had tiny holes in it which had some trapped moisture. Mine rusted in a Garage with low humidity. Steve got me the first set of Stainless ones which were perfect for the 70, but not shiny, so I sent them to Pauls chrome , and I guess its some work to make the copper and nickle stick right. Those tips went to MACN and did well eventually.
Honestly speaking, the tips that Gardner has are by Far and away Better than Any factory tips. I get many comments on mine, and guys get down and look closer and some measure hehe.
Ignatio, you will LOVE the tips when you get your Gardner exhaust.. because your car deserves it!

Transamric 04-22-2023 03:25 PM

Slight change of topic. Needed new tips for my '70. I have a few GM NOS sets of the '71-73 tips. So trusted Ames and bought their repro tips which arrived last week. Yes they are stainless with a pretty good shine. BUT,...these are made from two pieces and welded together. The clamp (vice?) grid marks on the junction of these two pieces are very noticable and go clear around the circumference. Couldn't be more disappointed. I could use the more slanted GM SR tips which are excellent quality but would like to keep the proper '70 only tip angle.
Decisions - decisions.

unruhjonny 04-22-2023 03:51 PM

Can you please post some pictures?

Transamric 04-22-2023 03:59 PM

Quote:

Originally Posted by unruhjonny (Post 6422747)
Can you please post some pictures?

Tried to take a few pics but the vise (grid?) marks won't picture well.
I'll try again to see if I can show the welded seam from the inside.

Ramairnacho 04-22-2023 06:57 PM

Can you change the 71 style to 70 and just be a little shorter.no one will know from street view? That's what I wanted to do with those nice 71 style that where 150. I think.72 has a 45 degree cut and 70 has a 22 degree cut. Easy fix with a chop saw and a metal cutting wheel. I'd use water to keep metal cool to minimize heat transfer stain. Just an idea.

Formulabruce 04-22-2023 09:36 PM

The stainless can be polished some and the weld isn't seen once installed.
I have cut late 71 tips and used on a 70 and looked fine. Tricky cut, need a bandsaw

Transamric 04-24-2023 05:55 PM

5 Attachment(s)
Quote:

Originally Posted by unruhjonny (Post 6422747)
Can you please post some pictures?

Had better success today with getting pics that show the grid marks.
Didn't mention before that the stainless end is not magnetic, as you'd expect. But as you move a magnet closer to the top end it starts sticking and is totally magnetic at the narrowed down top end. No doubt these are two piece construction.
Guess you could call these "nice 10 footers". But I didn't pay 200 clams for 10 footers.

Ramairnacho 04-24-2023 06:06 PM

Quote:

Originally Posted by Transamric (Post 6423282)
Had better success today with getting pics that show the grid marks.
Didn't mention before that the stainless end is not magnetic, as you'd expect. But as you move a magnet closer to the top end it starts sticking and is totally magnetic at the narrowed down top end. No doubt these are two piece construction.
Guess you could call these "nice 10 footers". But I didn't pay 200 clams for 10 footers.

Are those the ames repops? Are these our only option?

Held for Ransom 04-24-2023 06:13 PM

1 Attachment(s)
That's a lot worse than ones I have.

unruhjonny 04-24-2023 06:34 PM

/\ LOL

I didn't know they were ever stamped there!?


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