New-style neck for a 4.0 reservoir. Like the 3.5 version, it needs a 90 degree fitting added, per Howe's price list.
- Size: 4.0
- New style
- Requires 90 degree fitting
The updated 4.0 neck with radiator cap and 90 degree fitting is part 1017-1006.
Howe Performance part number 1017-1035.