Today, we look at installing a GM Performance LS3 into a 1970 Chevrolet Caprice. Removing the stock motor and transmission will shave several hundred pounds of weight as you replace your old drivetrain that can weigh as much as 850 pounds combined. With modern technology, you will have efficiency, power, and the reliability of a new car.

A few issues ago, we started prepping for our install. After assembling all of the pulleys and accessories, we figured out that the factory A/C would need to be relocated at a different time. Once all the components that we chose to use were bolted on, we were ready to start on the mocking up of the engine. With a brand new hoist and TD engine leveler that our buddy Brian Brennan let us borrow, it was easy to mock up the engine that was pulled in and out at least 12 times over a two-day period.

With these engines seeing an increase in availability through local dealerships or even directly from GM Performance, the LS transplants have become more popular. Now follow along, as we prep this LS3 for a Caprice transplant.

1. This GM Performance LS3 was ready to be transplanted.

2. To make the install easy, we pulled the front clip off the car.

3. The stock small-block 350 was a good design, but it needed to be upgraded with modern technology.

4. We pulled the whole engine and transmission out together so we could save time.

5. With a clean slate, we were ready to start on our Caprice transplant.

6. Calin helped us get our first measurements, so we could see the first obstacles that needed to be dealt with.

7. The stock oil pan did not work in our application and needed to be switched.

8. Here are three different oil pans that are currently the most popular. The first is the GM Camaro oil pan, but it did not work in our application, as the steering linkage won’t clear the oil pan. The second one is the LS retro-fit Holley oil pan. The third one is a GM muscle car oil pan, which cleared the steering, but hung below the frame. We needed to use the Holley pan to fit our job.

9. The Holley pan has a few benefits, including the sump baffle that will keep the oil from sloshing around the pan when braking, accelerating, and hopping.

10. Holley’s new LS Retro–fit Engine Oil Pan is designed to help! It provides maximum clearance to the chassis and ground, plus provides an OEM fitment for durability and proper sealing.

11. With the right oil pan, we were ready for the next obstacle.

12. It was time to install the Gearstar transmission.

13. The whole drivetrain went in together, so that all of the mounts could be checked.

14. We hung the engine over the stock motor mounts in order to get measurements and see if we could use the stock motor mounts.

15. There are several LS motor mount brackets to place your engine in the stock location. We opted to use the Energy Suspension brackets and mounts.

16. After checking the measurements, we realized that the stock motor mounts were to short and needed to be stretched.

17. The best thing to do in a case like this is to remove everything completely and just build our own.

18. We used the stock motor mounts so we could start building the new motor mount bases.

19. This ¼-inch plate would serve as the sides of the motor mounts.

20. Greg cleaned up the brackets.

21. We had to drill out the frame to make sure that the 3/8 bolts fit properly.

22. The nuts were welded to the frame to make it easier to pull them off, or in our case, to bolt them on.

23. There are several motor mounts on the market, and we used the energy suspension model because they were the easiest to modify for our application. These motor mounts pushed the engine forward a full inch.

24. With the heights measured out, we started tacking together the custom motor mount base.

25. The motor mounts were tack welded and ready to be welded together.

26. These mounts were ready to be painted and bolted onto the frame.

27. These motor mounts gave us the right height needed to give us clearance for steering, while ensuring that the oil pan would not hang below the frame.

28. These custom mounts cleaned up well.

29. The oil pan did not hang below the frame, which will keep the pan from cracking when the cross member scrapes the ground.

30. The motor was in place and ready to start and get plumbed.

31. From whatever view you have, these engines look good!

32. When installing LS motors, you need to make sure that you are running a radiator that will be able to handle the pressure that they create. We used a Becool bolt-in radiator for our project.

33. To make sure we had tolerance issues the core support brackets were trimmed down.

34. The transplant was in assembly as we wrenched away to fire up this engine.