The Muscle Rods LSX15 kit is a 1955-1957 Chevy LS conversion kit for Tri-Five cars. It mounts an LS engine and transmission with new frame brackets and a transmission crossmember. Order it for an LS with a T-56 or TR-6060, 4L60E to 4L70E, 4L80E or 4L85E, 6L80E to 10L90E, TH400, or Powerglide, TH350 or 4-speed.
What's in the kit
- Two motor mounts
- Two frame brackets
- Transmission crossmember
- Two transmission crossmember brackets
- Polyurethane transmission mount and spacers
- Installation bolt pack
Install requires drilling the frame for the frame brackets and the crossmember brackets. The guide shows each hole.
Transmission options
Pick the option that matches your transmission: T-56 or TR-6060, 4L60E to 4L70E, 4L80E or 4L85E, 6L80E to 10L90E, TH400, or Powerglide, TH350 or 4-speed. The guide gives the crossmember bracket height for the T-56 and the 4L60E.
Does my transmission need tunnel work?
With a T-56, the body seam in the transmission tunnel must be flattened. The guide shows relief cuts in the seam, then flattening it with a hammer and dolly.
Which oil pan works?
The kit is designed for the Moroso high clearance oil pan or the LH8 oil pan. The LH8 pan must be trimmed to clear the 1955-1957 frame, and the guide shows how much.
Headers, A/C and accessories
- Most OEM accessory drives can be used.
- Low-mount LS A/C compressors do not clear the frame. A Kwik Performance bracket kit moves the compressor up top.
- Muscle Rods headers bolt in with this kit.
- Check drag link to oil pan clearance: about 2 inches with the steering centered, about 3/8 inch at full left.
Read the 1955-1957 Chevy LS install guide before you order. To add headers, fuel, cooling and more, build your kit in the complete LS swap kit builder.