Jaguar Specialties
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Last Update 8-20-23

Chevy V8 Conversion Kits

88-94 XJ6, Vanden Plas, and Sovereign


Jaguar Specialties now offers Chevy V8 conversion kits and related parts for these models and here are some details:

Engine options-                Any 69-97 Chevy small block V8 ; carbureted or TBI/TPI/LT1 fuel injection
Transmission options-     Any T700R4, 4L60, or 4L60E (4 speed auto overdrive) transmission

Our kit is a bolt-in design; no welding, cutting or drilling are required on the car. The conversion utilizes 90+% off-the-shelf GM parts, just like our other conversions. Using standard parts makes the conversion less expensive, more reliable, and easier to maintain long term. A conversion manual is provided with the kit, and includes step-by-step instructions with plenty of photos, as well as a list of the original GM-style parts required to complete the job (available from you local auto parts store). When complete, everything on the car will function just as it did originally- all gauges will read correctly, shifter will operate the new trans properly, the AC will probably work better, and even the factory cruise control can be used with the new engine.

More detailed information on the XJ40 V8 conversion is below:

When Jaguar introduced the brand new XJ6 in 1987 (1988 in the US), it was a completely different car than the previous XJ6, and did not share a single part with the old model. This new, very advanced (for the time) car was called the XJ40 internally at Jaguar, and was a huge leap forward in refinement, handling, and luxury over the sedan it replaced. However, the initial 87-89 cars were offered only with a relatively small 3.6L 6 cylinder engine that was very short on horsepower for a car of this size/weight. From 1990 until the end of production in 1994, Jaguar offered a larger 4.0L engine, but still it was still short on power compared to other cars in its class. With a little more power, I imagined the XJ40 wouild be a great car. So Jaguar Specialties began a program to offer a Chevy V8 conversion package for this model, something that no other Jaguar conversion company has/had ever done.

The prototype car for this project was a pretty basic 88 XJ6 that received a 305 TPI (fuel injected) engine and T700R4 (auto overdrive transmission). Integrating the TPI into the XJ6 was fairly simple; the wiring was pretty straight forward, and hood clearance is adequate. The prototype conversion went very smoothly, logging many thousands of miles of testing to verify the components and end product. All gauges and electrics operate properly. The stock Jaguar shifter works with the (GM) T700R4 transmission perfectly and all stock detents line up as they should (and will also work with later model 4L60E transmissions). The cooling system consists of an off-the-shelf GM-based radiator (plastic tanks and high capacity aluminum core) and the same 17” Corvette/Camaro cooling fan we use on the conversions for the earlier cars. The air conditioning system functions perfectly (better than before, I think) with the GM radial compressor, and the fabrication of the required hoses required easily available standard AC fittings. This was the easiest AC installation I have ever done on a Jaguar conversion. Even the factory Jaguar cruise control functions perfectly with the Chevy engine. In the end, the car ran and operated basically just as it did when stock, except of course for the noticeable increase in power (and that’s just with a well used 305….). The improvement in performance is fantastic.

Below please find some photos of the completed prototype 88 XJ40 V8 car.


A more recent conversion project was my 94 XJ12 (last year of the XJ40). That car was converted using a 95 Camaro LT1/4L60E drivetrain (300+ hp). To see more details on that project, Click Here

Please see the "V8 Conversion Price List" page for current pricing on this kit and related parts