In short: Magnaflow Street Series crossmember-back system, part number 16842, for the 1968 Chevrolet Corvette 5.3L and 1969-1973 5.7L according to Magnaflow (early C3 years). Stainless steel, 2.5 in (63.5 mm) mandrel-bent piping, two straight-through mufflers, dual split rear exits, satin single-wall 2.5 in (63.5 mm) turndown tips. Moderate outside, mild inside.
Corvette C3 1968-1973: an exhaust worthy of a collector car
The early C3 Corvettes, from 1968 to 1973 with their Coke-bottle curves, are now sought after by collectors. Under the long bonnet sits the small-block V8: 5.3L in 1968, then 5.7L according to Magnaflow. On a car this old the exhaust has often been changed several times, sometimes with ill-fitting generic parts that hang under the body and spoil the original sound.
The 16842 was designed to put things right. It covers the exhaust behind the crossmember with stainless components, developed with 3D scanning to sit on the original mounts. The dual split exits, with discreet satin tips turned down towards the ground, respect the look of a classic instead of imposing a modern style. As for sound, the V8’s deep bass comes through at moderate exterior and mild interior levels according to Magnaflow: enough to enjoy drives and meets without tiring passengers or onlookers.
To be clear: Magnaflow publishes no power figure for this system and we do not claim one. The point lies elsewhere: a clean, durable exhaust true to the spirit of the car.
A crossmember-back system: what it means
Magnaflow calls a system “crossmember-back” when it replaces the exhaust from the chassis crossmember to the exits. The front section, from the manifolds to the crossmember, stays in place. In the Street Series, the 16842 consists of:
- 2.5 in (63.5 mm) main piping, mandrel bent with no pinching in the bends.
- Two straight-through mufflers that let the V8 speak.
- Dual split rear exits, one on each side.
- Welded-on 2.5 in (63.5 mm) tips, satin finish, single wall, turndown cut.
- Durable, corrosion-resistant stainless steel, valuable on a car that may spend long months in the garage.
- Direct fit, built by CNC robots.
Technical specifications
| Feature | Detail |
|---|
| Magnaflow part number | 16842 |
| System type | Crossmember-back |
| Series | Street Series |
| Pipe diameter | 2.5 in (63.5 mm), mandrel bent |
| Mufflers | 2 straight-through mufflers |
| Exits | Dual split rear, one on each side |
| Tips | 2.5 in (63.5 mm), satin finish, welded on, single wall, turndown cut |
| Sound level | Moderate exterior, mild interior |
| Material | Stainless steel |
Fitment
Magnaflow lists the 16842 for the early C3 Corvette model years:
| Make | Model | Years | Engine |
|---|
| Chevrolet | Corvette (C3) | 1968 | 5.3L V8 |
| Chevrolet | Corvette (C3) | 1969-1973 | 5.7L V8 |
C3 Corvettes from 1974 onwards are not on Magnaflow’s list. On a collector car, past modifications are common: check the model, year and the engine actually fitted; if in doubt, our technical team will answer before you order.
Fitting and precautions
- The system connects behind the crossmember and uses the original mounts.
- Manifolds and front pipes up to the crossmember stay in place.
- New gaskets and clamps at the joints: on a car over fifty years old, do not try to reuse the old ones.
- If a non-original exhaust was fitted before, check the condition and position of the hangers before fitting.
- Line up both tips at the same height and check clearance to the fibreglass body and the differential.
- Re-tighten cold after the first outings.
- For a collector car, professional fitting is a reassuring choice.
Availability and lead times
Magnaflow builds its systems in the United States and keeps part of the range in its European warehouse in Italy. If your system is available there, we receive it within a few days and it usually ships to you in about a week. Otherwise it comes from the US warehouse by sea container (one shipment every six to eight weeks): allow about three months. We confirm the lead time when you order; to know it beforehand, call us on +33 1 34 67 70 31.
Important: this system is ordered specially for you from Magnaflow. Please check your vehicle’s model, year and engine carefully before ordering (our technical team can check with you): a system ordered by mistake cannot be taken back, exchanged or refunded.
Frequently asked questions
1. Does it respect the original look of my C3?
It keeps dual split exits and discreet satin tips turned towards the ground, with nothing flashy.
2. What does “crossmember-back” mean?
The system replaces the exhaust from the chassis crossmember to the exits; the front section stays in place.
3. My Corvette is a 1975: will it fit?
No, Magnaflow lists the 16842 for the 1968 to 1973 model years only.
4. Will the sound suit drives and car meets?
Magnaflow rates it moderate outside and mild inside: a present voice without excess.
5. Do I need to change the engine or carburettor?
No, the system fits in place of the existing exhaust.
6. How much power does it add?
Magnaflow publishes no figure for this system and we do not claim one.
The workshop chief’s tip: once the system is fitted, listen to it twice. First cold, at start-up: a metallic tick or a hiss at a joint reveals a leak or a pipe touching, easier to hear before everything has expanded. Then after twenty minutes on the road: the sound should have rounded out and any stray noises disappeared. If they persist when hot, switch off, let it cool and redo the alignment rather than tightening harder. On a carburetted V8, also wait for the idle to settle before judging.
Restoring or maintaining a C3 Corvette and want to be sure of your choice? Contact the STR Performance technical team before ordering: we will check the 16842’s fitment with your car.
