1977-1990 Caprice LS Trans Mount Adapters

Swapping a late model gearbox into a 1977-1990 Caprice or Impala with an LS? These four BRP adapters give a CTS-V or Camaro six-speed, or a 6L90E, 8L90E or 10L90E automatic, a traditional transmission mount pad. That pad then bolts to a BRP crossmember.

2 TR-6060 family and 2 automatic adapters
Automatic adapters made for BRP crossmembers
8L90E piece also fits the 10L90E

The 1977-1990 B-Body Sure-Fit crossmember, engine mounts and headers are on the 1977-1990 B-Body LS page. Tunnel notes come from the 1977-1990 B-Body LS install guide.

$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

1977-1990 Caprice and Impala transmission mount adapter parts

Six-speed manual adapters for the box B-Body

Late GM automatic adapters for the box B-Body

Back to the 1977-1990 B-Body swap

Adapter specifics

CTS-V T-56 and standard TR-6060 bracket: laser cut, CNC bent, jig welded 3/16 steel, black powder coat, hardware in the box.
MG9 bracket: made for the high-torque TR-6060 used behind the LSA in the CTS-V, hardware included.
6L90E piece: fits the 2009-2014 CTS-V automatic tailshaft housing.
8L90E piece: one adapter for either the 8L90E or 10L90E tailshaft.

1977-1990 B-Body tunnel and crossmember notes

Per the guide, a 6L80E or 6L90E needs tunnel modifications at the tail shaft housing area in these cars.
A T-56 needs tunnel work around the shifter, the guide says.
The 4L60E and 4L80E fit with no tunnel modifications.
The crossmember sits on two brackets in the original holes, with a secondary Z bracket backing up the driver side.

Notes from the 1977-1990 B-Body LS install guide. Adapter details come from product names and BRP product text.

1977-1990 B-Body LS transmission mount adapter FAQ

Does a 6L90E need tunnel work in a 1977-1990 Caprice?

Yes. The 1977-1990 B-Body guide says the 6L80E and 6L90E need tunnel modifications at the tail shaft housing area.

Which adapter suits a regular TR-6060 in a box Caprice or Impala?

The Cadillac CTS-V T-56 / standard TR-6060 adapter. The MG9 adapter is only for the high-torque TR-6060 from the CTS-V.

Do these adapters bolt to the BRP 1977-1990 B-Body crossmember?

BRP says the two automatic adapters are to be used with its transmission crossmembers. The TR-6060 adapter text does not say, and the B-Body guide does not mention adapters.

Is there an adapter for the 10L90E in a 1977-1990 B-Body?

The 8L90E adapter covers both the 8L90E and 10L90E tailshaft. The B-Body guide does not list either transmission, so check tunnel clearance on your car.