Exoracing Extended Intake Exhaust Stud Kit For Honda B/D/K/H/F-Series

Why Use Exoracing Extended Intake Exhaust Studs?

Old Honda manifold hardware has usually had a hard life. On B, D, H, F and K-Series engines, the original studs and bolts may have been heat-cycled, removed, refitted, rounded or left to corrode for decades. Reusing weak hardware can make manifold jobs more frustrating and increase the risk of snapped studs, loose nuts, leaks or poor clamping force.

These Exoracing extended studs solve two common problems at once. First, they replace old manifold hardware with 304 stainless steel studs and nuts. Second, the 50mm extended length gives more thread engagement when you are using thicker gaskets, thermal intake gaskets or aftermarket manifolds with larger flanges.

The hex tip makes installation easier than the old two-nut method because you can wind the stud into the cylinder head with an Allen key or hex socket. That makes them a sensible upgrade during an intake manifold swap, exhaust manifold change, turbo manifold install or engine bay refresh.

If you are building a matching Honda bay, these also sit naturally with the Exoracing titanium intake exhaust manifold nut and stud kit, Exoracing dress-up bolt and washer kit and Exoracing K-Series flush spark plug cover.

Honda Engine Fitment Guide

This kit is aimed at Honda engines that use M8x1.25 manifold hardware. Always check your original hardware before ordering, especially if the engine has been swapped, modified or fitted with aftermarket manifolds.

When Should You Fit Extended Studs?

Purchase Includes:

• 10 x Exoracing extended M8 intake exhaust studs
• 10 x Exoracing 304 stainless steel M8 nuts
• 10 x Exoracing thermo nylon washers
• 1 x Exoracing lifetime warranty

Features:

• M8x1.25x50 extended stud size for common Honda manifold applications
• 304 stainless steel studs and nuts for corrosion resistance
• Extended length helps with thermal gaskets and thicker aftermarket manifold flanges
• The hex tip head makes installation easier than the two-nut method
• Includes thermo nylon washers
• Suitable for Honda B, C, D, F and H-Series intake or exhaust applications
• Suitable for Honda K-Series intake manifold applications
• Full kit weight: 218g
• Includes Exoracing lifetime warranty

Exoracing Extended Stud Kit Installation Guide:

These studs are best installed while the intake manifold, exhaust manifold or turbo manifold is already removed or loosened. We also have a full intake or exhaust stud installation guide with extra images and video support.

1. Confirm the original manifold hardware is M8x1.25 and check that the extended 50mm length is suitable for your manifold and gasket setup.
2. Remove the old, rusted studs or bolts from the cylinder head. If the manifold is still in place, leave a few fixings finger-tight until you are ready to swap them.
3. Clean the threads in the cylinder head carefully so the new studs can seat correctly.
4. Install the Exoracing extended studs using an Allen key or hex socket in the hex tip.
5. Fit the manifold or gasket, then add the thermo nylon washers and stainless nuts.
6. Tighten the nuts evenly across the manifold so the flange pulls down squarely.
7. After a few heat cycles, recheck the nuts because manifold hardware can settle as it expands and contracts.

Technical Specifications:

Frequently Asked Questions

Will these fit my Honda engine?

They are designed for Honda engines using M8x1.25 manifold hardware. They fit B-Series, C-Series, D-Series, F-Series and H-Series intake or exhaust applications, and K-Series intake manifold applications.

Can I use these on a K-Series exhaust manifold?

No. The current fitment guidance is K-Series intake only. Do not order these for a K-Series exhaust manifold unless you have checked your specific setup and confirmed the thread, length and clearance.

Why are these extended?

The 50mm extended length helps when using thicker intake thermal gaskets, aftermarket manifolds or larger manifold flanges where standard hardware may not give enough thread engagement.

Do they include nuts and washers?

Yes. The kit includes 10 extended M8 studs, 10 304 stainless M8 nuts and 10 thermo nylon washers.

Do I need to retighten them after installation?

Yes. Recheck the nuts after a few heat cycles because manifold hardware can settle as it heats up and cools down.

Notes:

• Please confirm your original manifold hardware is M8x1.25 before ordering.
• Check that the 50mm extended stud length has enough clearance for your manifold, gasket and surrounding parts.
• Recheck the nuts after a few heat cycles.
• Professional installation is recommended if any original hardware is seized or damaged.