SPL Phonitor SE review: an analogue headphone amplifier that is VERTEX DOMINAR SPL PRO AUDIO Structured Product Labeling DDReg Pharma SPL letter logo design in illustration. Vector logo, calligraphy. SPL Parts PRO Solid Subframe Conversion Bushings (SSB) are designed to allow S14 S15 subframes to be mounted on the S13 chassis or vice versa. Our Solid Bushings prevent the subframe from "bouncing around" under drivetrain torque or suspension load, maintaining optimum suspension geometry and reducing wheel hop. Our slide in shim system allows you to quickly raise or lower the subframe to fine tune the roll center anti squat behavior to your preference. Raising the subframe will compensate roll center for a lowered car at the expense of increasing anti squat. Lowering the subframe will decrease anti squat at the expense of roll center. This is NOT Formula Drift legal! Subframe swaps are not currently legal under FD regulations. SPL Parts PRO series Bushings are precision CNC machined from 6061 T6 Billet Aluminum for excellent fit. Our bushing kit also includes optional rubber isolation washers to reduce noise transfer from the subframe to the chassis. Sold as complete kit for one car. Made in the USA. Applications: 1989 1994 Nissan 240SX (S13) Installation Instructions: SPL Solid Subframe Conversion Bushings This Part Fits: Year Make Model Submodel 1991 1993 Nissan 240SX Base 1991 1992 Nissan 240SX LE 1989 1994 Nissan 240SX SE 1989 1990 Nissan 240SX XE