I have incorporated the two together on this page. The main different between the two is that the TR4 had a live Rear Axle and the TR4A had a Indipendant differential with drive shafts

 Permitted modifications supported by documented evidence. 


4 Cyl OHV.  2138cc


Points and condenser. The Dynamo may be replaced by an alternator.

Carburation/Fuel System

Twin SU’s or twin Weber DCOE’s 

An electric fuel pump may be used to replace the mechanical unit.


4 Speed with overdrive unit. 


The fitting of a concentric clutch slave cylinder assembly is not allowed. 

Back Axle.

TR4 Live axle.

TR4A Independent differential with drive shafts.

Salisbury plate type LSD is allowed 

Suspension. Front.

Coil spring front suspension. Standard rubber bushed mountings.Telescopic shock absorbers 


TR4 Leaf springs Lever arm shock Absorbers. 


The fitting of a dual master cylinder or any other type of device providing a simultaneous action on all four wheels and divided action on two wheels is permitted providing the original brake pedal and pivot point are used.

The remote brake bias adjuster must be positioned so that it cannot be adjusted by either the driver or co-driver when normally seated in the car.

A Hydraulic handbrake is not allowed.


Solid brake disc with 2 pot cast iron brake calipers.



 Wheels and Tyres.

15” rim size. 6” maximum for Road rally,

Tyre size and profile as per MSA year book.


Fibre glass bonnet or boot lid. Composite side windows.                                                                      

Alloy centrally mounted replacement petrol tank.