70-72 Monte Carlo LS Trans Mount Adapters

Putting a six speed manual or a 6L90E, 8L90E or 10L90E behind the LS in your 1970-1972 Monte Carlo? These BRP adapters bolt to the tailshaft so the gearbox can sit on a conventional transmission mount and crossmember.

Two manual and two automatic adapters
Outer crossmember brackets use factory holes
Four speed automatics keep the stock tunnel

The 1970-1972 Monte Carlo LS install guide shows the tunnel cuts these longer gearboxes need. Mounts, headers and tanks are on the 1970-1972 Monte Carlo 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

1970-1972 Monte Carlo transmission mount adapters

TR-6060 and T-56 manual adapters

6L90E, 8L90E and 10L90E automatic adapters

Matching an adapter to your gearbox

A Monte Carlo running a CTS-V T-56 or a Camaro TR-6060 uses the 3/16 inch steel adapter, which ships with bolts.
Pulled an MG9 out of an LSA powered CTS-V? That high-torque TR-6060 has its own bracket.
The 6L90E adapter is for the 2009-2014 CTS-V automatic tailshaft housing.
One automatic adapter serves both the 8L90E and the 10L90E, and BRP says to pair it with its crossmembers.

Monte Carlo transmission fitment notes

Per the Monte Carlo guide, the floor has to be opened up for a T56, TR6060, 6L80E, 6L90E or 8L90E.
The 4L60E, 4L65E, 4L70E, 4L75E and 4L80E slip into the original Monte Carlo tunnel.
The Monte Carlo kit includes a transmission crossmember, two outer brackets and a polyurethane mount with spacers.
A gold preload plate and spacers go between the poly mount and the transmission before the crossmember bolt is snugged.
Header routing assumes a floor shifter, so a column shift car needs linkage changes or a cable linkage.
Plan on a different driveshaft length, and the factory clutch Z-bar cannot be reused.

Notes from the 1970-1972 Monte Carlo LS install guide.

1970-1972 Monte Carlo LS transmission mount FAQ

Will a TR-6060 fit a 1970-1972 Monte Carlo without cutting the floor?

No. The Monte Carlo guide lists the TR6060 among the transmissions that need tunnel modifications, and shows the cuts and filler panel.

Do I need an adapter for a 4L80E in my Monte Carlo?

This page only carries adapters for the TR-6060, CTS-V T-56, MG9, 6L90E, 8L90E and 10L90E. The guide says the 4L80E fits the factory tunnel.

Where does the Monte Carlo crossmember bolt in?

The guide says the outer crossmember brackets go into existing holes in the frame, and the crossmember slides onto them.

Does the guide cover the 10L90E?

No. It names the 8L90E but not the 10L90E. The 8L90E adapter is listed for both tailshaft housings.

1970 - 1972 Monte Carlo LS Transmission Mount Adapters