TVR Engineering worked with Andy Rouse, a Rover Tuning specialist to produce a blueprinted engine, turning out an extra 85 bhp (63 kW; 86 PS), taking it to a claimed 275 bhp (205 kW; 279 PS).

A stronger clutch, limited slip differential and wider Yokohama tyres were fitted to help get the extra power down onto the road.

The styling of the car was also improved - or at any rate made more aggressive - with a deeper front air dam, and a rear under body aerofoil.

Production of the modified Rover V8 was handled by different engineering companies throughout the car's life with most units being produced by North Coventry Kawasaki (NCK); which company was subsequently purchased by TVR to become their in-house engine division, TVR Power.

At the customer's request, further engine work could be performed taking the V8 to 4.2 L capacity - thus creating the '420SE' in the process, of which only seven were built in 1986 and 1987.