Build Any RB Your Way — With Spool-Engineered Strength

Whether you're building a high-revving RB20 for the track, a tough RB25 street motor, or a full-send RB34 drag weapon, one thing’s for sure — the RB platform has endless potential.

At Spool Imports, we've engineered a complete range of forged conrods, custom pistons, and billet crankshafts to suit every RB combination — including Neo and SOHC setups. If you're building it, chances are we’ve got it.

Here’s a breakdown of the most popular RB builds and how Spool can help you put together the perfect rotating assembly.

RB20 – The High-Revving Underdog

The factory 69.7mm stroke makes the RB20 a lightweight, high-revving platform. Ideal for compact cars or budget builds, and a great candidate for forged internals if you want to push boost.

Forged H-Beam Conrods for RB20
Custom Pistons for performance builds

RB24 – The Sleeper Hybrid

Our RB24 combo uses an RB20 block with an RB25/26 crank and head. We run a custom 82mm piston that allows clearance for RB25/26 conrods in the RB20’s narrow bores.

RB25/26 forged conrods
Custom pistons with correct pin height and bore

RB25 – The Street Hero

With a 71.7mm stroke and strong aftermarket support, the RB25 (and RB25 Neo) is one of the most popular RBs for serious street and track builds.

H-Beam and I-Beam conrods
Pistons to suit RB25 and RB25 Neo heads

RB26 – The GT-R Classic

The RB26 shares its block casting with the RB25, but features a solid lifter head and twin-turbo layout. It’s a high-revving engine that benefits greatly from forged upgrades.

RB26-spec forged conrods
Pistons to suit standard or oversize bores

RB28 – Smart Stroker Upgrade

The RB28 uses a 77.7mm billet crankshaft to deliver better torque without needing a tall-deck block. We use standard rod lengths and custom pistons to suit.

RB28 Billet Crankshaft
Standard-length conrods
Custom pistons with adjusted pin height

RB29 – The Perfect Balance

Our RB29 kit uses a 79mm billet crank to create a strong, high-performing engine while keeping standard block height.

RB29 Billet Crankshaft
Standard-length rods
Custom pistons for RB25 or RB26 heads

RB30 – The Aussie Favourite

The RB30 block with an 85mm stroke offers proven torque and strength. We offer complete packages for all head types including Neo and SOHC.

RB30 Billet Crankshaft
H-Beam or I-Beam rods
Pistons for RB25, RB26, Neo and SOHC heads
All Wheel Drive Adaptors to RB30 your GT-R heads

RB32 – Torque With Response

The RB32 uses a 91mm stroke crank with standard rod length and a custom piston for ideal rod ratio and piston stability.

RB32 Billet Crankshaft
Standard-length conrods
Custom pistons matched to stroke

RB34 – Maximum Displacement

The RB34 features a 94mm billet crankshaft for massive cubes and torque. Built for high-boost and high-horsepower applications.

RB34 Billet Crankshaft
Standard-length H-Beam or I-Beam conrods
Custom pistons tailored to your head and compression goals

Why We Use Standard-Length Rods + Custom Pistons

At Spool, all our stroker kits are engineered to run standard-length conrods. Instead of using longer or shorter rods, we adjust the piston pin height (also known as compression height) to match the stroke change. This keeps engine geometry close to factory while improving reliability.