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Mike D'Ambrogia's 1974.5 TR6 V8 conversion ("engine wars")

Mike D'Ambrogia · 74.5 TR6

Triumph TR6

britishv8.orgStarted April 13, 2009, with updates through 2018

Read the full write-up at britishv8.org ↗

Photo: britishv8.org

A 1974.5 TR6 that went through three V8/V6 swaps before landing on a Chevy 350

Mike D'Ambrogia chronicles a long-running engine saga for his TR6, trying a Buick 455, then a Toyota 1UZFE, before settling on a GM 350 L05 as the practical choice. The write-up is a candid, first-person log of false starts, a brutal donor-van teardown, and the fitment problems that killed each earlier attempt, useful reading for anyone weighing engine options for a TR6 swap.

Specs

As the owner states it.

Engine
GM 350 L05 TBI (previously a Buick 455, then a Toyota 1UZFE)
Cooling
Undecided, trying to use the full-size radiator from the GM donor van
Exhaust
Undecided
Transmission
Initially a 700R4, with a Borg-Warner T5 set aside for rebuild
Rear Axle
R230 LSD 3.73, required major surgery to install
Front Suspension
Stock
Rear Suspension
Stock, planning to upgrade to heavier halfshafts
Brakes
All stock (master, front, rear)
Wheels/Tires
TA Radials
Body Mods
Fiberglass front clip, removable inner fenderwells
Interior
Black
Electrical
To be rewired, using a combination of Dan Masters parts and other aftermarket vendor products

Parts used

What the owner names in the 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 3

  • Buick 455 big block V8

    First engine tried; shipped in from Ohio, ultimately removed as too large for the TR6 frame

  • Toyota 1UZFE V8

    Second engine choice, installed on the rolling frame; removed after valve covers fouled the steering column and brake booster space

  • GM 350 L05 TBI V8

    Third and final engine choice, harvested from an 88 GM G20 conversion van donor

Gearbox & Drivetrain 4

Body & Trim 1

  • Fiberglass front clip

    Used as a body modification on the TR6

Tools & Workshop 1

  • Sawzall reciprocating saw

    Bought new specifically to cut apart the donor van and speed engine extraction

Other 1

  • Mockup engine block

    Free block obtained from a contact in San Jose, used to test-fit the Buick 455 during the frame swap experiment

Photos

All 2 pictures in the write-up, in the order they were posted, shown from britishv8.org. A picture opens larger here, with the way through to the page it is on.

Photo: britishv8.org
Photo: britishv8.org

How it was done

The spark: a Cobra goes by

After driving his tired stock TR6 to his kid's baseball practice, the owner kept thinking about a bigger engine. Seeing a 427 Cobra pass by settled it: he decided to go big rather than stay stock, and began researching heavy American V8 swaps.

First attempt: Buick 455

He ruled out the large Chevy big blocks as too heavy and bulky, and instead sourced a Buick 455, shipping a motor in from Ohio and getting a free mockup block from a contact in San Jose. He experimented with a frame swap and cut into the old firewall to fit the engine, but after years of work concluded the 455 was simply too much motor for the TR6 frame and pulled it before finishing.

Second attempt: Toyota 1UZFE

Having liked the smoothness of the 1UZFE in his own SC400, he had California Hot Rods in Sonora install the Toyota V8 into the rolling frame along with an R230 LSD differential sourced from a turbo ZX. The engine went in cleanly, but once the body was reunited with the frame, the valve covers proved too tall and wide, fouling the steering column and leaving no room for the brake booster.

Back to basics: choosing a Chevy 350

Rather than keep chasing an exotic fit, he returned to the BritishV8 how-it-was-done archive and decided to take the proven route: a GM small block Chevy 350, with an eye toward eventually building it into a 383 stroker for more performance.

Harvesting the donor van

He found an 88 GM G20 conversion van on Craigslist with a 350 TBI and 700R4 combo, negotiated it down to 500 dollars, and confirmed decent compression numbers despite high mileage. He stripped the nasty interior, then began cutting the body apart to harvest the drivetrain, computer, wiring harness, fuel system and other parts.

The battle to pull the engine

Removing the engine from the van turned into an all-day fight, requiring a new sawzall and cutting away body sections like the fiberglass side step just to access bolts and the driveline. He came away with hard-won lessons about draining fluids first, needing more shop space, and the value of raw cutting tools.

Restarting the driveline work years later

Nearly a decade after the original posts, with the SBC motor already worked on but stalled, he moved the project to a new garage and began talking to a local mechanic about finishing the driveline. The plan became a minimal, streetable track-day build rather than a show car, keeping the option to return the car to stock later.

A summary in our own words. The full account, with all its detail, is the owner's: read it at britishv8.org ↗

Worth knowing

  • Drain all fluids from a donor vehicle before pulling the engine, not after.
  • Have a sawzall or similar cutting tool on hand when dismantling a donor van.
  • Avoid using a van as a donor vehicle, they are far harder to extract engines from.
  • Allow plenty of garage space to spread out parts, and a sealed floor makes cleanup easier.
  • Check engine height and width against steering column and brake booster clearance before committing to a swap.
  • Sometimes the proven, unglamorous engine choice is better than chasing an exotic fit.

britishv8.org

Read in full on 6 September 2026. The work, the words and the pictures are Mike D'Ambrogia’s; this page is a catalogue of them in our own words, and a signpost.

Read the full write-up at britishv8.org ↗

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