Mustang Exhaust Header Clearance

The following is a list of exhaust manifolds and headers that our customers have told us have (or have not) worked for them. Our systems are not limited to these headers by any means, but you can use them as a routing style reference for your own headers. It is the routing style that is important, not the name brand. You can look these up to see if yours have similar routing styles. Usually, we only hear back when a header does NOT fit – most fitment issues are on the driver’s side where the U-Joint assembly connects the column to the rack. We have provided some measurements at the bottom of the page to help determine if your headers will work with our kits. On the list below, if it says that a dimple is required, we recommend you heat the header tube with a torch, then take a large socket and wrap it in a rag and gently tap a smooth dimple into the header with it. Customers have successfully done this with coated headers and not damaged the coating.
PLEASE NOTE: To date we do not know of ANY aftermarket headers that works with the 351C (though there is a manifold that works, but it is not stock). Custom or modified headers may be required. More info on the 351W listed below.
PLEASE NOTE:  If you are concerned about header clearance, this may be a solution: Ron Morris Performance Adjustable Motor Mounts! These have front to back and side to side adjustment!

Small Block:

– Dart Headers with a 351 – DO NOT FIT

– Doug’s Tri-Y Headers with a 289 – Slight dimple may be required on pass side – FIT

– Doug’s Tri-Y Headers with a 302 – DO NOT FIT

– Doug’s Headers with a 351 – DO NOT FIT

– FPA (Ford Powertrain) 9430331 Longtube with a 5.0 Conversion – DO NOT FIT

– FPA (Ford Powertrain) 9430347 Longtube with a 302 – DO NOT FIT

– (FPA NOTE: FPA claims they have headers that will work with our kit on small blocks, but we have not been able to confirm part numbers. You may be interested in checking with them at

– Hedman #88300 (Full Length) – No Problem – 289, 302, 351W – FIT
***NOTE – Hedman #88300 did NOT fit with McLeod scatter shield and cable clutch on a ’70 Mustang with a 302 engine rebuilt as a 331, with RHS heads (dimple would be required).

– Hedman Shorties w/ 302 – Dimple required driver’s side – FIT

– Hedman #88400 Shorites with 289 in a ’65 – Dimple required on #6 – FIT

– Hedman #88650 3/4 length w/ 351W – FIT

– Hedman #88650 Shorties w/ 302 – FIT

– Hedman #88406W2 Shorties w/ 302 – DO NOT FIT

– Hedman #HTC 88408 Shorties w/ 289 – Dimple required driver’s side (at collector) – FIT

– Hedman #88304 Tork Step w/ a 351W – DO NOT FIT

– Hedman #88668 w/ 351W – Dimple will sometimes be required driver’s side – FIT

– Hedman Tri-Ys (older version) – Dimple required on drivers side – FIT

– HiPo Manifolds (67 Mustangs with the high performance (aka HiPo or K code) 289 engines) – DO NOT FIT

– Hooker 6208 with a 351 – DO NOT FIT

– Hooker 6133 with a 351 on 67 Coupe – DO NOT FIT

– Hooker Competition #6901 – DO NOT FIT, (but may clear with our new bracket – we have not tested it yet)

– Hooker Super Comp with a 351C – DO NOT FIT

– Hooker Super Comp #61161195 with a 351W – DO NOT FIT

– JBA 2 1/4″ with 5.0 Conversion (Full Length) – No Problem – FIT

– JBA Shorties with 302 – Most fit with no problem, but some have to dimple the header (see JBA #s below) – FIT

– JBA 1650S-2 (Shorties) with 302 – No problem with most hydraulic clutch & clutch cable setups. – FIT

– JBA 1650S (Shorties) with 302 – Dimple most likely required.

– JBA Shorties with 351W – Most no problem with clutch cable setup with smaller tube sizes – FIT

– MAC (Full Length) – No Problem – FIT

– Patriot Clipster Shorties on a 65 with a 5.0 – DO NOT FIT, but may clear with new bracket

– Sanderson Block Hugger Shorties with a 351C – No Problem, but customer had custom hoses made – FIT

– Stock Manifold – DO NOT FIT WITH EITHER 351C or 351W, but see manifold note below or Hedman note above:

– Stock Manifold D00E-9431B – No Problem with 351W in a 69 (apparently the manifold is off a 70 Fairlane) – FIT

– Stock Manifold From 71-73 351 Cleveland – No Problem with 351C (apparently if you use a manifold from 71-73 Mustangs with a 351 C it will work with our kit. We have not tried it ourselves, but a customer told us it worked for him. – FIT

Big Block:

– (1967) Tri-Y – No Problem – FIT

– (67-68) FPA (Ford Powertrain) Tri-y – No Problem with FE cars ( – FIT

– (1967-68) Ford Powertrain 390 (Lock or staggered bolt, cast iron Cobra Jet) – DO NOT FIT

– (1967) Stock High Performance Manifold – DO NOT FIT

– (67-68) JBA Short Style – Dimple Required – FIT

– (69) JBA Tri-Y – Slight Driver’s Side Dimple Required, slight passenger’s bracket clearancing required – FIT (if you are willing to tweak things a little)

Click on the images below for measurements for Steeroids clearance.

Please click on the links below to see enlarged pictures of header clearance pictures and measurements. If there is a header clearance issue it is usually with the u-joint assembly, so this should be able to help you determine where that u-joint assembly will be located. The “Steeroids Engine Mount Measurement” is measured from the back of the engine mount attachment on the frame/shock tower. The center of the pinion is at about 10.19″ from that point. As you can see the rest of the rack sits between 9″ and 10.5″. Those are good numbers to use when checking clearance. Basically once you use these photos to determine where the pinion shaft on the rack will be located you can then draw a line to the steering column about 1.5″ from the fire wall. This is where the u-joint assembly will attach to the column. If there are no headers in the way, chances are the Steeroids kit will work fine with your headers.