About JTR and Stealth Conversions

JTR (Jaguars That Run) was the brainchild of Mike Knell. In the mid-1980s he began fitting Chevrolet V-8 engines into Jaguars and published a manual on how to successfully accomplish the swap.

Jaguars with engine problems can be purchased quite cheaply, and installing a Chevrolet drivetrain usually costs less than repairing the Jaguar engine. The Jaguar V-8 conversion provides greater reliability, economy, and in many cases, performance.

JTR went on to perfect the V-8 engine swap for a number of other cars including the Datsun Z, the Volvo 200 Series, and the Chevrolet S-10 Truck. These vehicles are converted to Chevrolet power primarily for performance reasons, not economy or reliability.

We publish manuals that take you step by step through the conversions, offering a wealth of details and advice from our years of experience.

You can read excerpts from the manuals by selecting from the list below.

Stealth Conversions—for engine swap parts & mounting kits
Stealth Conversions is the Parts Division of JTR. We offer special products to assist you in the successful completion of your engine swap. Our newly simplified site navigation integrates details about the part you need into the page you use to order it. No more jumping back and forth between a part description, excerpt from a manual, and order pages cluttered with many unrelated items. Improved search and filtering, plus collections of parts by vehicle and part type, simplify finding what you need.

JTR's conversion manuals cover the following types of information, as well as details specific to each model:
  • Brackets and Motor Mounts
  • Engine Dress
  • Automatic Transmissions
  • Driveshaft and Differential
  • Engine Compartment
  • Installation
  • Electrical
  • Tachometer Calibration
  • Speedometer Calibration
  • Cooling System
  • Fuel System
  • Exhaust
  • California Smog Laws
  • Air Conditioning
  • Vehicle Speed Sensors

    Simplicity, Cost, and Refinement
    Our V-8 conversions are done in the simplest most practical, reliable, and economical way we can find. We stick with factory parts and readily available high-quality aftermarket parts as well as producing our own parts when the available parts simply won't do. Our finished conversions are made smog legal according to California smog laws in effect at the time of the conversion.

    Almost anybody can just drop a V-8 into an S-Truck, a Datsun Z, or any other of these cars and make it run. JTR has differentiated itself by refining conversions so they perform like factory built vehicles: smooth, quiet, reliable, and functional. Everything must function as stock: air conditioning, shift linkage, clutch release, instrumentation, cooling, and smog controls. The swap must be repeatable. People reading the manuals need to achieve a swap of similar completeness and quality.

    What we write and the parts we supply are based on our experience converting cars, which are tested and driven daily by different drivers and under varying conditions. We work out all the bugs and problems, so you can do your conversion right the first time. We would rather have a functional, drivable vehicle than one that goes from place to place on a trailer or behind a tow truck.

    JTR Publishes Books
    JTR does not do engine swaps for the public. JTR only does swaps in order to write the books and determine what parts are needed to make the swaps. Typically, it takes over a year to write a book. Many hours of research and development go into each swap book to ensure that it guides you and other readers through a practical, repeatable swap process.

    We take engine swaps quite seriously. Most of the cars shown in our manuals are used by friends and family for daily transportation. These cars are not "weekend warriors" driven only occasionally. These are vehicles on which their owners depend. We enjoy seeing people doing good engine swaps and we have written our manuals to help you succeed.

    Clean Air
    The conversions shown in these manuals are California smog legal. We have found that the people who live in California and do not do a smog legal conversion, usually do a substandard conversion. The reason for this is: if they don't spend the time and money to make it legal, they also don't spend the time and money to do the rest of the conversion properly. See our chapter on California Smog Laws from the Chevrolet S-10 Truck V-8 Conversion Book.

    Vehicle Speed Sensors
    Stealth Conversions has been offering aftermarket Vehicle Speed Sensors (VSS) for engine swaps since 1991. The speed sensors are smog legal for engine swaps, and have been issued CARB EO #D-371. Without a VSS, the Chevrolet Fuel Injected engines will not run correctly, and they will not pass a California style smog test. Stealth Conversions has several types of vehicle speed sensors designed for easy installation into vehicles that were not equipped with vehicle speed sensors. Also available are relocated Reluctor Rings for 4L60-E transmissions, which allow running speedometer cables.

    Our manuals were written for people who have a good education in car mechanics, lots of automotive experience, and a good selection of shop tools. They were not written for people who have a tight budget or who are in a hurry.

    Our experience shows that maybe half the people who start a conversion finish it in one to six months, and half are not finished even after six months! Engine swaps are not easy. They require good information and painstaking attention to detail. We have seen a lot of dangerous mistakes, such as incorrect fuel hoses, exhaust too close to brake lines, linkages that get stuck...

    This is not meant to scare you. It is meant to warn you about the gravity of the decision to undertake a conversion. If it sounds expensive and time-consuming, it is! It is also very rewarding when it is done right.