Get big exhaust performance & stay warm all at the same time with the new Big Tube Ultra Heater Boxes from AC Industries!

Until now the classic VW enthusiast has had to make the choice between running a high-performance 1-5/8″ exhaust header system or to keep a functioning heater in their car. Well friends, the day has come where now you can have the best of both worlds with AC Industries’ new 1-5/8” Big Tube Ultra Heater Boxes!

Only AC Industries’ Big Tube Ultra Heater Boxes feature a premium O.E. style cast aluminum internal heat sink as shown in this cutaway image.

AC Industries’ 1-5/8” Big Tube Ultra Heater Boxes are the only performance production heater box to feature a premium O.E. style cast aluminum internal heat sink (as shown*). The cast aluminum heat sink slows down the incoming air flow to maximize the heat transfer. This resulting optimized heat transfer efficiency provides the ultimate warmth available for your ride.

It is this premium O.E. style cast aluminum internal heat sink feature that sets AC Industries’ 1-5/8” Big Tube Ultra Heater Boxes above the rest. The other 1-5/8″ heater boxes available on the market today only have hollow shells lacking internal heat sinks. This design is inefficient as it solely relies on the heat transfer from the bare head pipe in the hollow of the box to warm the air.

The new AC Industries Big Tube Ultra Heater Boxes feature a 1-5/8″ head pipe and laser cut thick two bolt head mounting flange. The OEM style outside stamped shell has a heavy duty gray powder-coating. The heater boxes also come with an extra pair of laser cut two bolt flanges for the installer to weld in place making the installation of the exhaust system easier. All OEM style heater box connections work with the Big Tube Ultra Heater Boxes, including the factory bellow tubes from the exit of the heater box to the body on 1600 engines. The outer shells feature tabs to install the factory lower engine cooling tins.

The AC Industries 1-5/8″ Big Tube Ultra Heater Boxes will be available in two different kits:

255158L/R kit includes:
• One pair of 1-5/8″ Big Tube Ultra Heater Boxes
• Two laser cut bolt thick flanges

298158L/R kit includes:
• One pair of 1-5/8″ Big Tube Ultra Heater Boxes
• Two laser cut bolt thick flanges
• Two lever kits
• Four 1-5/8″ high quality exhaust gaskets

Both AC Industries Big Tube Ultra Heater Box kits offer your ride the improved exhaust flow with the big 1-5/8″ header tubes with the added benefit of warm air your heater channels to keep you toasty on those chilly mornings. Don’t settle for less, order your AC Industries‘ new 1-5/8” Big Tube Ultra Heater Boxes today!