Turbo LS-powered HQ Belmont

Chris Pilkington was a nitrous SBC diehard until he was swayed to the turbo-LS side of the Force for his snoozy, 622hp HQ Holden

Photographers: Steve Kelly

Queensland’s Christopher ‘Stof’ Pilkington has spent over a decade around fast cars, including nitro funny cars, but he took a sharp left turn with his HQ Belmont build.

First published in the February 2023 issue of Street Machine

“I’m a small-block nitrous guy, but I went to Powercruise in a mate’s VE SS with an 850hp turbo LS, and that was it,” Stof laughs. “I’ve copped so much shit off my mates about the LS!”

Despite his mates’ ribbing, the appeal of an LS was all too obvious for Stof. “The LS engines are impressive for what they are,” he says. “They’re so streetable and useable, but you can still take them to events like Powercruise and thrash them. People who complain about them haven’t had a good one, because for a good, reliable street car, you just can’t beat the LS!”

Stof scored this super-clean HQ Belmont from inside his own family circle after several years of healthy pursuit. “My father-in-law had it for about five years with a small-block, ’Glide and nine-inch in it, and it took me about that long to convince him to sell it to me,” he laughs. “I weaselled it out of him, tidied up the engine bay, and then it went through a few changes.”

“I’ve got a flat bonnet for it now. The reverse cowl was from when it had the nitrous set-up”

After his transformative VE SS experience, Stof started planning an LS build for the Quey and worked out a way to minimise his out-of-pocket expenses using his skills as a mechanic. “I bought two VE SS cars and parted them out to fund the build,” he says. “So, between the two cars, the engine basically paid for itself!”

That engine is an L98 Gen IV 6.0-litre, which scores some nice upgrades over older Gen III mills, including a drive-by-wire accelerator, improved ECU, and deep-breathing, rectangle-port cylinder heads.

The engine has been cammed at some point, but Stof doesn’t know anything about it other than that it’s a small aspirated one. “The engine is basically a stock-bottom-end set-up with beehive valve springs, upgraded oil pump and timing chain, and 1000cc Xspurt injectors,” he says.

The party-starter is a Proboost SXE480 turbocharger, sitting on a set of manifolds from Darcy at KillaBoost and with boost control from a Turbosmart wastegate and Boost Tee. “I’ve got a switch on the dash so I can choose between 7psi wastegate spring pressure or 10psi,” Stof says.

“It makes 622hp at the hubs on 10psi and E85, and that is plenty given it has 195-wide tyres. It has the VE drive-by-wire accelerator in it, and it’s set up so it doesn’t end up on the limiter, and you can just mash it.”

A manualised, transbraked Powerglide and nine-inch send all the grunt to those tortured 14-inch tyres, while Stof set the rear end up with double-adjustable Viking coil-overs and adjustable upper and lower arms on stock mounting points. “My neighbour, Steve Carkeet, has a pretty full-on HQ called CUMN4U, so this thing has inherited a few parts from him,” he explains.

Stof and ET Chassis did the exhaust, with the four-inch dump pipe off the turbo merged into the twin three-inch system from the old combo. This could be replaced later on when a new, spicier set-up is ready – yep, now that Stof has tasted the sweet LS life, he wants more. “We’ll build an LY6 iron-block 6.0-litre for it, because everything else is built to take 1000hp,” he explains. “This engine has plenty more in it, but it really is more of a cruiser.”

Ever the forward-thinker, Stof already has plans for what will happen to the current L98 once the LY6 is good to go. “My son has an HQ wagon, so when I want more, he’ll probably end up with this stuff,” he says.

As for the HQ in its current form, Stof is unsure about whether he wants to take it to the drags. “I’m in two minds about running at the strip, because I don’t want to get booted,” he admits. “I have a set of 235 Nankangs [for it], just to see how it goes at the off-street drags at Powercruise.”

Stof Pilkington
1974 Holden HQ Belmont

Engine: 6.0L L98
Cam: Mystery!
ECU: Siemens E38
Turbocharger: Proboost SXE480
Transmission: Powerglide
Converter: Red Diamond billet 4200rpm
Diff: 9in, 31-spline billet axles, full spool, US Gear 3.4:1 gears
Power: 622rwhp

Pete at Surface Correction & Protection; Jamie at ET Chassis & Race Cars; Nudge at Mr Skid Towing; Terry at Paramount Performance; Ben at Grounded Auto Electrics; last but not least, my wife Hope and kids Linc and Dougie