73-77 A-Body LS Trans Mount Adapters

Transmission mount adapters for LS swaps in 1973-1977 A-Body cars like the Cutlass, Chevelle, Monte Carlo, El Camino and Regal. They give a TR-6060, CTS-V T-56, MG9, 6L90E, 8L90E or 10L90E tailshaft a conventional mount pad to sit on the crossmember.

Fits manual and late automatic tailshafts
Outer crossmember brackets bolt to factory holes
4L60E to 4L80E keep the stock tunnel

Tunnel cuts for the longer gearboxes are shown in the 1973-1977 A-Body LS install guide. Mounts, the crossmember and headers are on the 1973-1977 A-Body LS swap page.

$39.99 Cadillac CTS-V T-56 / standard TR-6060 Trans Mount Adapter

$39.99 MG9 high-torque TR-6060 Trans Mount Adapter

$39.95 Cadillac CTS-V 6L90E Transmission Mount Adapter

1973-1977 A-Body transmission mount adapters

Six speed manual adapters

6L90E and 8L90E/10L90E automatic adapters

Which adapter for which gearbox

Standard Camaro TR-6060 or Cadillac CTS-V T-56 in a 1973-1977 Cutlass or Chevelle: the laser cut steel adapter.
MG9, the high-torque TR-6060 behind the LSA: its own MG9 adapter.
6L90E from a 2009-2014 CTS-V: the 6L90E tailshaft adapter.
8L90E or 10L90E: a single adapter covers both, made for BRP crossmembers.

1973-1977 A-Body transmission notes

The 1973-1977 guide lists tunnel work for the T56, TR6060, 6L80E, 6L90E and 8L90E.
That work means cutting the tunnel top, widening it at the rear and closing the gap with a filler panel.
Four speed automatics from the 4L60E to the 4L80E go in the factory A-Body tunnel unmodified.
The polyurethane trans mount gets the gold plate and spacers underneath to preload it.
The factory clutch Z-bar is not reusable, and driveshaft length may change.

Notes from the 1973-1977 A-Body LS install guide.

1973-1977 A-Body LS transmission mount FAQ

Does a T56 fit a 1973-1977 Cutlass or Chevelle without tunnel work?

No. The 1973-1977 A-Body guide includes the T56 with the gearboxes that need the tunnel cut, widened and patched.

Will a 4L80E need one of these adapters in my 1973-1977 A-Body?

These adapters are for the TR-6060, T-56, MG9, 6L90E, 8L90E and 10L90E only. The guide says the 4L80E fits the factory tunnel.

Which adapter is for a 10L90E?

The 8L90E Transmission Mount Adapter, which BRP lists for both 8L90E and 10L90E tailshaft housings. The guide does not mention the 10L90E.

Can I use my factory clutch linkage with the swap?

No. Per the 1973-1977 A-Body guide, the factory clutch Z-bar cannot be used with this kit.

1973 - 1977 A-Body LS Transmission Mount Adapters