270bhp 5.7-litre Chevy V8-powered 1976 Jaguar XJ6 Series 2

Slightly lower than standard

American English JAGUAR XJ6 CHEVY V8

style=”simple” size=”6″]Joe Brooks had a pretty straightforward philosophy when it came to putting together this V8-powered Jaguar XJ6, ‘it’s for having a laugh, making a nice noise and doing some big skids,’ laughs Joe, ‘I love cars like this that don’t have to be taken too seriously.’ As with 90 per cent of everything else in our modern world, Joe’s project began with a search on eBay.

‘I’d always wanted an old Jag and this was £1100 back in 2016, the seller had a place right next door to some banger racers and they’d been asking to buy the car for ages but he always said it was too nice to be raced. In fact after I bought the car he even offered to deliver it to me to get it well away from them.’ Ironically Joe also used to rookie banger race… but not anymore.


‘I always used to see Jaguars getting wrecked on the track and I really wanted to save one,’ admits Joe. ‘Although after I won it I did think, “what have I done?” The Jag had apparently been sitting in a garage for 25 years but the guy reckoned it was solid.’ Oddly enough, it was. ‘To be honest it was actually silly how clean it was. It needed two new front wings since they were pretty rusted away under the indicators where they usually rot out, but otherwise it was really good. It had never been welded anywhere and the floors and boot were solid. I gave the paint a quick blow over in the original British Racing Green and then put on a new vinyl roof – I was cursing for hours all the way through that. The worst thing was the ancient fuel in the tanks had solidified, in the end I heated it up with Halogen lamps but as it dripped out you could snap it off with your hands…’


The 1976 Jaguar XJ6 had only two previous owners, oddly for a right hand drive car it was also apparently American spec. ‘It had these strange marker lights on the corners which I’d never seen before; a mate of mine reckoned it was for the American market. I took them off the rear end when I replaced the front wings. The gearbox wasn’t great, but it generally drove really nicely. It was obviously a car that had been cared for by a club member, who had presumably then died, since it was full of old show plaques.’

That might have been the end of the story since Joe was quite happy cruising the car about with the silky smooth original 4.2-litre straight-six. ‘One day it did a bolt in the head. I was driving along and bang! Out popped a head bolt and dented the bonnet. I wrapped it in insulation tape and beat it back into place with a rock. I then filled it back up and drove it for another two weeks.’ Despite such sympathetic and effective repairs Joe really needed another engine, preferably a V8. He made a few calls and before long was standing in a yard belonging to some banger racing mates. ‘I asked if they had a V8 for sale and one of the lads pointed to a Cadillac limousine – don’t ask me what year since I’m not really into Yanks, all I know is it was an old one – and said it had a 350ci Chevy with a TH400 in it. They attacked it with a digger and 20 minutes later the engine and gearbox were out.’


A useful thing to know is that several English car manufacturers including Jaguar found the smoothest and strongest automatic gearbox they could put behind one of their engines was the General Motors Turbo-Hydramatic. That meant the TH400 gearbox that Joe was currently hauling home was going to be virtually a perfect fit. But what about the 5.7-litre American engine…? ‘It went in fine, like it was made for it.

The engine mounts virtually lined up perfectly, I got back onto eBay and used Jag V12 mounts combined with 45-degree Chevrolet ones.’ We should point out that Joe doesn’t completely know the origins of that 350ci block, although chances are high it’s a Chevrolet motor and chances are even higher that it wasn’t originally factory installed in that Cadillac limo either. We also said the ‘box was virtually a perfect fit, ‘the American-spec TH had a different bellhousing and shaft, although I had to get two new U/Js it turns out the Jaguar and Cadillac/ Chevrolet ones are identical. The gear lever is cable operated, which made it simple to get it to fit in the correct place in the centre console.

I made up a 20mm by three-inch bar piece and drilled a load of holes in it, then bolted the gearbox in place using the standard gearbox mount, made up a bracket for the cable and then fed it through the bar using the most convenient hole for the Jag shifter.’ The gearbox also now uses an electronic torque convertor for fourth gear.

‘The rear axle is now a 3.88:1 with a Powerlock from a Jaguar XJS – as well as noise I wanted skids. The propshaft needed to be shortened slightly – about three or four inches – which was handled by my mate John. He sleeved it then Tig welded it. The Series 2 cars like this one had a cable driven speedometer but the XJS diff I put in has an electronic speedo drive so I had to buy a XJS controller unit and wire it up to a Series 3 speedo. That was a bit of guesswork since all the wires were different random colours. I also used a Series 3 Jaguar steering rack since it looked like the standard one wouldn’t clear the Chevy V8’s starter motor and the series 3 one has a shorter stem. Although looking at it now it probably would have fitted okay.’

The engine is virtually standard, ‘it’s got the shittiest heads you can get but then the whole lot was only £500 including the gearbox. I bought some Vortec heads but it turned out two of the valves were cracked. It will get updated in the future though, I’m planning on LS springs, a high lift cam – I’ve got a 480 to go in – and bigger valves. There’s just so many performance parts available for Chevies it’s mind blowing. It’s currently 270bhp but I’d like to get 400 after a complete rebuild. I originally put on an Edelbrock 750 cfm carb but that over fuelled, so now it runs a 650. It now has electronic ignition too.

‘It was running hot and it’s a car I was going to drive every day so I put in a twin-core XJS radiator – it lined up perfectly with the engine. It’s now got an oil cooler and a gearbox cooler too. Either seven- or nine-row each, they came from eBay. I also redid all the heater piping behind the dash in copper – I’m a plumber by trade.’ Speaking of pipes the exhaust is a 2.5-inch pipe on each side going in through the rear subframe with a Cherry Bomb muffler on each one.


Bodywise the only real change is removing the Leaper from the bonnet, which Joe did as part of the repaint. The wheels are the standard steels with the centre caps removed; ‘the typical banger racer look’ smiles Joe. You’ll have no doubt spotted though that the Jaguar sits a lot lower over those wheels… ‘It’s on air. A mate of mine was building a Series 3 Jag on airbags so we had a few chats about the best way to do things and another mate is a hydraulic engineer, so between us it was straightforward to work out. There are twin shocks on the rear, they’re Volkswagen, I think made for a Beetle, so that’s four air shocks on the rear combined with a single coilover bag on each side. I fabricated tube mounts so it drops a further two inches lower than the standard suspension. It’s rated for two and a half tons.’

The front uses aftermarket air bags on the front – Joe doesn’t recall where from – and Gaz adjustable shocks from a BMW Mini. ‘I wanted a simple up and down system without electric solenoids – no dancing or hopping. It drops to the ground or lifts up four-inches for driving. I’m going to plate up the tie bars to strengthen them; it’s fine at the moment but is going to need uprating when I rebuild the engine.’ Brakes are the standard discs all round.

‘I fitted a new dashboard top and the headlining was sagging like they all do so I bought some leopard print upholstery – you can only see it if you look right inside. I found it on eBay, there was a woman making homemade teddy bears and I asked for the biggest piece of material she could get, turned out to be just the right size for a Jag roof. I’m going to do the boot to match. There’s a new water temperature gauge in the dashboard purely because the old one had stopped working and the centre console now houses the suspension controls, but otherwise inside it’s pretty much as I found it.

‘I’ve not spent thousands, just what money I had. It was mainly built with bits I had laying around and I didn’t measure anything – I just guessed or cut it to fit. I did consider putting the 4.0-litre XKR engine in but they’re a really advanced car and I’m not sure I could be bothered with sorting all that wiring. I didn’t think I’d get so heavily involved with this conversion to be honest.

‘One compromise was having to slightly cut down the air filter to clear the bonnet, I’ll have to chop out some reinforcement on the underside of the bonnet and add strengthening somewhere else. Or maybe fit an E-type style bonnet bulge. There have been unexpected improvements such as mpg since the V8 isn’t working as hard as the six was, at 80mph it’s still under 2000rpm. I’ve not checked the weights but I suspect the Jag and the Chevy engines weigh about the same, there’s no difference in handling although it gets a bit wallowly at speed with the air suspension.

‘I’d love to hear from a previous owner but I bet he’d hate what I’ve done. Probably the funniest moment yet was when I was out for a drive one Sunday and the local manor house was hosting a Jaguar club meet, all these beautiful old restored classic Jags and I accidently drove into the middle of it… One lovely old boy let me out in front of him at the junction and I couldn’t resist; I waved thanks and then pulled out sideways on opposite lock with the tyres screaming, which is exactly what the car was built for. I bet he thought “wanker,” but it was really funny…’

Chevy small block V8 of unknown providence. Airbagf suspension is either up or down. This is the latter… Electrnoic dizzy. 650cm carb. ‘Banger racer style.’ Marlene from Only Fools and Horses would love this… …but possibly not this. Original Jag shifter. Modern temp gauge replaces unreliable Jag version. Wrapped exhaust manifolds. Except the tyres. Series 2 XJ6 in park mode sits lower than a PM’s approval rating.


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