Sign in

← All builds

Phil Erikson's 1974 MGB GT V6 conversion

Phil Erikson · 1974 MG MGB GT

MG MGB

BritishV8: the site for enthusiasts of modified British sports cars2014

Read the full write-up at BritishV8: the site for enthusiasts of modified British sports cars ↗

Photo: BritishV8: the site for enthusiasts of modified British sports cars

A 1974 MGB GT rebuilt with a GM 3.1L V6 by Killer B Conversions

Phil Erikson owns the prototype MGB GT V6 conversion built by Dann Wade before Wade's kit business became Killer B Conversions and later British Car Conversions. The car pairs a Pontiac-derived 3.1L V6 with a Camaro five-speed, and has been modestly lowered and retrimmed inside. It is notable for being the car Ken Costello himself praised and autographed at a show, and for having covered many miles reliably since 1996.

Specs

As stated in the original write-up.

Engine
GM 3.1L V6 from a 1993 Pontiac Grand Prix, stock camshaft and aluminum heads, multi-port fuel injection
Fuel & Ignition
Mallory Comp 9000 distributor, Mallory Promaster coil, MSD plug wires, Accel vane-type fuel pump, Haltech F3 fuel management
Cooling
Rebuilt MGB radiator with three-row core, Meziere electric water pump, electric pulling fan
Exhaust
Custom headers and flanges, H-pipe, dual exhaust exiting driver's side, dual Supertrapp glasspack mufflers
Transmission
Borg Warner T5 5-speed from a 1983 Camaro (0.73:1 fifth gear), custom mount, Hurst shifter, 10 inch single plate clutch, Oldsmobile Quad 4 diaphragm pressure plate
Rear End
Stock MGB Salisbury axle, open differential, 3.909:1 gears
Front Suspension
Rebuilt lever shock absorbers, lowered springs, stock rack and anti-sway bar
Rear Suspension
KYB tube shocks, lowered leaf springs sourced from Australia
Brakes
Stock MGB brakes with EBC Green Stuff pads, cross-drilled rotors, earlier-model MGB master cylinder
Wheels/Tires
Superlite 14x6 eight-spoke aluminum wheels, gold centers and polished rims, Dayton 195/65R14 tires
Interior
Stock MGB instruments, stripped Abingdon pillow dashboard in wrinkle-finish black, Dodge Omni center console, Pioneer DEH245 stereo, four speakers, power antenna, saddle upholstery, honey carpet, Momo steering wheel
Body
Bumpers removed, stainless wire mesh grille, Sebring style fascias, shaved side markers, Euro-spec taillights
Weight
2180 pounds (1100 front / 1080 rear)
Performance
14.9 second quarter mile at 92 mph, 33 mpg on road trips
Completed
1996

Parts used

Parts named as used in the original write-up, grouped the way the Parts page groups them. Where one of the shops we index lists the same thing for this car, it is shown underneath with a link to the shop.

Engine 1

  • GM 3.1L V6 engineGeneral Motors

    Donor engine from a 1993 Pontiac Grand Prix, chosen for aluminum heads and bigger valves

Fuel & Ignition 6

Cooling 3

Gearbox & Drivetrain 5

Suspension & Steering 4

Brakes 3

Wheels & Tyres 2

  • Superlite 14x6 eight-spoke aluminum wheelsSuperlite

    Gold centers and polished rims fitted to the car

  • Dayton 195/65R14 tiresDayton

    Tires fitted to the Superlite wheels

    In the shops
    Dayton Wire Wheels ↗Moss Motors – Triumph TR6/TR250· $578.75 USD

Body & Trim 3

Interior 5

Electrical 1

Other 4

  • Custom exhaust headers and flanges

    Equal-length headers built for the V6 swap, one routed around the steering u-joint

    In the shops
    Exhaust Adapter, Header Flange to Dual 1-3/4in ↗Good Parts· $129.00 USD
    Exhaust Adapter, Header Flange to Single 1-7/8in ↗Good Parts· $89.00 USD
  • H-pipe

    Connects the dual exhaust system

  • Supertrapp glasspack mufflersSupertrapp

    Adjustable mufflers with removable baffle plates for tuning sound

  • Custom MG V6 badge

    Badge marking the V6 conversion on the exterior

Photos

30 pictures collected from the write-up, in the order they were posted, shown from BritishV8: the site for enthusiasts of modified British sports cars. A picture opens larger here, with the way through to the page it is on.

Phil Erikson's 1974 MGB GT with GM 3.1L V6Photo: BritishV8: the site for enthusiasts of modified British sports cars
GM 3.1L V6 from a 1993 Pontiac Grand Am.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Among those advantages: aluminum cylinder heads and bigger valves.Photo: BritishV8: the site for enthusiasts of modified British sports cars
One header primary wraps around the steering u-joint.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Delphi Automotive alternator from a 1993 Chevrolet S10.Photo: BritishV8: the site for enthusiasts of modified British sports cars
The accelerator pedal is connected via cable to this side of the throttle body.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Manual operation of the idle air control valve!Photo: BritishV8: the site for enthusiasts of modified British sports cars
Meziere electric water pump.Photo: BritishV8: the site for enthusiasts of modified British sports cars
MGB radiator, rebuilt with three-row core.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Stock aluminum cylinder heads.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Passenger side exhaust header.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Spectre Performance PowerAdder air filter.Photo: BritishV8: the site for enthusiasts of modified British sports cars
To Mike and Dann: well done! - Ken CostelloPhoto: BritishV8: the site for enthusiasts of modified British sports cars
The starter motor has been relocated from one side of the engine to the other.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Exhaust pipe routing. Note also KYB telescoping shock absorbers.Photo: BritishV8: the site for enthusiasts of modified British sports cars
SuperTrapp mufflers feature a stack of up to twelve baffle plates.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Polished exhaust tips.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Stock MGB front brakes, upgraded with EBC Green Stuff pads and cross-drilled rotors.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Quilted headliner!Photo: BritishV8: the site for enthusiasts of modified British sports cars
Momo steering wheel. Hurst shifter.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Dodge Omni center console. Pioneer DEH245 CD stereo radio.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Back seats were standard equipment on the MGB GT model.Photo: BritishV8: the site for enthusiasts of modified British sports cars
The backrest of the back seat folds forward to lengthen the cargo shelf.Photo: BritishV8: the site for enthusiasts of modified British sports cars
One of the rear speakers.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Custom MG V6 badge.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Stainless steel wire mesh grille insert.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Shaved marker lights and Euro-spec taillights.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Superlite 14x6 eight spoke aluminum wheels with gold centers and polished rims.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Sebring style fiberglass rear valance.Photo: BritishV8: the site for enthusiasts of modified British sports cars
Donate Now!Photo: BritishV8: the site for enthusiasts of modified British sports cars

How it was done

Origins of the car

This MGB GT is the original prototype that Dann Wade built before turning his V6 swap into a kit business, first as Killer B Conversions and later British Car Conversions. Phil Erikson bought it from Mike Maloney, Wade's first customer. At a 2003 show in St Louis, Ken Costello himself inspected the car and signed an aluminum plate in the engine bay, calling it the car he felt should have been built.

Choosing and fitting the V6

The donor engine is a GM 3.1L V6 pulled from a 1993 Pontiac Grand Prix, a front-wheel-drive version chosen for its aluminum heads and larger valves despite the extra work of adapting it. The starter was relocated to suit the FWD layout, and one header primary was routed around the steering u-joint to keep tube lengths even.

Fuel, ignition and electrical adaptation

The engine kept its factory multi-port injection but gained a Haltech F3 engine management system, Mallory distributor and coil, and MSD plug wires. A Spectre Performance air filter sits on top, while a Delphi alternator from a 1993 Chevy S10 handles charging. The factory stepper-motor idle air valve could not fit under the bonnet, so a manual cable control was rigged for idle instead.

Cooling and exhaust work

An MGB radiator was rebuilt with a three-row core and paired with a Meziere electric water pump and a pulling electric fan to manage the V6's heat. Custom headers and flanges feed an H-pipe and dual exhaust that exits on the driver's side through a pair of adjustable Supertrapp glasspack mufflers.

Driveline and chassis changes

Power goes through a Borg Warner T5 five-speed taken from a 1983 Camaro, carrying a low 0.73:1 overdrive top gear, mounted on a custom bracket and shifted with a Hurst lever. A 10 inch clutch with an Oldsmobile Quad 4 pressure plate handles engagement. The stock MGB Salisbury rear axle and open differential were retained. Both ends were lowered about 1.25 inches, with KYB tube shocks at the rear.

Brakes, wheels and body details

Braking stays largely stock MGB but gets EBC Green Stuff pads, cross-drilled rotors, and an earlier-model single circuit master cylinder in place of the federally mandated tandem unit. The car rolls on Superlite 14x6 eight-spoke wheels with gold centers and polished rims, wrapped in Dayton tires. Bumpers were removed in favor of Sebring style fascias, a wire mesh grille, shaved marker lights and Euro-spec taillights.

Interior finish

Inside, the Abingdon pillow dashboard was stripped and refinished in wrinkle-finish black paint, paired with a Dodge Omni center console holding a Pioneer CD stereo. Moss Motors supplied saddle-colored seat and door trim while Prestige supplied honey carpet. A Momo wheel and quilted headliner round out the cabin, with speakers added in the console and cargo area.

A summary in our own words. The full account, with all its detail, is in the original write-up: read it at BritishV8: the site for enthusiasts of modified British sports cars ↗

Worth knowing

  • Front-wheel-drive versions of the GM 60-degree V6 bring aluminum heads and bigger valves worth the extra adaptation work.
  • Equal-length header primaries may require routing one pipe around the steering u-joint.
  • A factory stepper-motor idle air control valve can clash with the MGB bonnet, so plan a manual alternative.
  • Relocating the starter is needed when swapping a FWD-spec engine into a rear-wheel-drive car.
  • Swapping to an earlier single circuit master cylinder is an option when adapting American drivetrain parts.

FIND YOUR NEXT IDEA

Explore

VideosSearch videos and spoken topicsPartsFind parts from specialist storesBuildsLearn from other people’s projectsSocialsIdeas from the communityTechnical & communitiesGuides, advice and owner clubsGalleryBrowse photos and inspiration
Phil Erikson's 1974 MGB GT V6 conversion | Restomod Life