Men in Sheds – MGB Costello V8


The MGB Costello V8 conversions are often more valuable than their factory counterparts

Little known in the United States, the MGB Costello V8 is admired as one of the most historically important variants of the car produced. A skilled engineer and talented racing driver, Ken Costello saw a need to increase the performance of the standard MGB without resorting to measures that would adversely affect reliability.

Later version with lower profile intake manifold

Later version with lower profile intake manifold

Costello considered the alternatives and decided that the best answer was to install the BOP 215 3.5-liter V8 that was used in a variety of Rover models – introduced to the UK in 1967 – into an improved MGB to create a car that was faster than most contemporary E-Types and 911s and carried a 140 mph top speed.

Costello reached the same conclusion as BMC, but two years earlier

Costello reached the same conclusion as BMC, but two years earlier

Early cars used the BOP 215 to P6 specification with twin SU carburetors, fiberglass bulged hood and a distinctive egg crate grill. Braking and suspension upgrades completed the package and the engineering and finish work were completed to better than factory standards. Conversions were performed to both roadster and GT models with the majority of conversions made to the more expensive coupe.


Lowered stance results from the improved suspension

BMC’s introduction of its own V8 model – two years after introduction of the Costello – proved the death knell for the bespoke MGB Costello V8 since it was more expensive to purchase than the factory built car. Costello modified approximately 225 cars between 1970 and 1974. Today, a high number of survivors remain and are highly sought after collectibles that usually demand higher prices than their factory built counterparts.


MGB Costello attractive from any angle


By Johnny Oversteer

Images provided by Sussex Sports Cars.

'Men in Sheds – MGB Costello V8' have 3 comments

  1. September 7, 2015 @ 2:39 am derekdynamo

    Rest in Peace Ken Costello


  2. April 27, 2023 @ 12:18 pm Richard M Fairclough

    Probably the best MG that MG never made !


  3. August 17, 2023 @ 4:59 am Michael Sharman

    When Ken built these cars he upset Rover or whoever stopped supplying him with new engines, I believe the last few had reconditioned second hand units. Ken was also known for his very quick Hillman Imps


Would you like to share your thoughts?

Please note: technical questions about the above article may go unanswered. Questions related to Moss parts should be emailed to

Your email address will not be published.

© Copyright 2022 Moss Motors, Ltd. All Rights Reserved.