FFG F100 Coyote Swap H-Pipe Bulkhead Adapter Kit
Turn the heater off and watch the passenger head climb. That is the Coyote swap problem nobody warns you about. With the heater loop closed; coolant flow to the passenger side head gets restricted. One head runs hot; the other stays cool; and the ECU pulls the truck into limp mode on the drive you have been waiting two years for. The H-Pipe fixes the flow. Our bulkhead adapter is CNC-machined from solid aluminum and mounts straight to the firewall - raw machined or black anodized. It is the same piece we put in every Coyote swap we build; not because it is nice to have but because we have seen what happens without it. Three ways to buy it. The Premium kit is a full -08AN braided setup with billet connectors; line and fittings. The OEM+ kit runs Dorman 90-degree connectors and heater hose with all the clamps and O-rings. Adapter Only is for the builder who already knows exactly what he is plumbing. Engineered coolant flow; heater on or off. Buy it now or buy it after the first hot day.
Install Level: Intermediate - firewall mounting and coolant plumbing; the system must be bled after filling
Three kit levels published: Adapter Only; Premium (billet connectors and -08AN braided line); OEM+ (Dorman 90-degree connectors and heater hose).
Premium kit includes the billet bulkhead adapter; billet -08AN connector fittings A and B in black anodize; 12 ft of -08AN black braided soft line; 2 barb AN fittings; 4 straight AN fittings; 4 90-degree AN fittings; an AN O-ring plug; 6 ft of heater hose; 4 worm drive hose clamps and all O-rings and hardware.
OEM+ kit includes the billet bulkhead adapter; 2 90-degree heater hose connectors; 15 ft of heater hose; 8 worm drive hose clamps; 4 barb AN fittings; 4 90-degree AN fittings; an AN O-ring plug and all O-rings and hardware.
Adapter Only is the machined bulkhead adapter by itself; you supply all lines; fittings and clamps.
Keep Your Coyote Cool
Fat Fender Garage Coyote H-Pipe Bulkhead Adapter
Your Coyote swap runs perfect – until you turn off the heater and watch that passenger side head climb into the danger zone. We've seen it happen too many times. Coolant stops flowing where it needs to go, temperatures spike, and suddenly you're dealing with limp mode when you should be enjoying the drive.
Why Every Coyote Needs an H-Pipe
Here's the problem: when your heater's off, coolant flow to the passenger side head gets restricted. That head starts running hot while the other stays cool, and your ECU throws the truck into protection mode. Not exactly the performance you swapped in a Coyote for.
We've used H-Pipe solutions in every single Coyote swap we build because they work. This isn't just good practice – it's essential insurance for your engine's longevity.
Precision-Machined Solution
Our Billet Aluminum H-Pipe Bulkhead Adapter mounts directly to your truck's firewall with the precision fit you expect. CNC-machined from solid aluminum, available in raw machined or black anodized finish. This isn't a band-aid fix – it's engineered cooling flow that keeps both heads happy, heater on or off.
Three Ways to Build It Right
Premium Kit – The Complete Solution
Everything you need for a professional AN-line setup:
• Billet Aluminum H-Pipe Bulkhead Adapter (Raw or Black Anodized)
• Billet Aluminum -08AN Connector Fittings A & B (Black Anodized)
• 12' -08AN Black Braided Soft Line
• 2 Barb AN Fittings
• 4 Straight AN Fittings
• 4 90-Degree AN Fittings
• AN O-Ring Plug
• 6' Heater Hose
• 4 Worm Drive Hose Clamps
• All O-Rings and Hardware
OEM+ Kit – Clean and Reliable
Professional results with traditional heater hose connections:
• Billet Aluminum H-Pipe Bulkhead Adapter (Raw or Black Anodized)
• 2 90-Degree Heater Hose Connectors
• 15' Heater Hose
• 8 Worm Drive Hose Clamps
• 4 Barb AN Fittings
• 4 90-Degree AN Fittings
• AN O-Ring Plug
• All O-Rings and Hardware
Adapter Only – For Custom Builders
Just the precision-machined adapter for those building their own solution:
• Billet Aluminum H-Pipe Bulkhead Adapter (Raw or Black Anodized)
Material: billet aluminum; CNC-machined from solid
Finishes: Raw Machined or Black Anodize
Mounting: bolts to the truck firewall
Premium kit line: 12 ft of -08AN black braided soft line
Premium kit fittings: billet -08AN connector fittings A and B (black anodize); 2 barb AN; 4 straight AN; 4 90-degree AN; AN O-ring plug
Premium kit hose and clamps: 6 ft heater hose; 4 worm drive hose clamps
OEM+ kit: 2 90-degree heater hose connectors; 15 ft heater hose; 8 worm drive hose clamps; 4 barb AN; 4 90-degree AN; AN O-ring plug
All O-rings and hardware included with both complete kits
Variant count 6 across two finishes and three kit levels
Listed price 54.99 USD for the Raw Machined adapter only
Installation manual published as a PDF
The bulkhead adapter mounts to the firewall and plumbs the H-Pipe coolant loop for the Coyote engine.
