Engine swap and matching computer system

Asked by #ColeWorld Jan 11, 2018 at 12:31 PM about the 2003 Mercury Grand Marquis GS

Question type: Maintenance & Repair

Hey, If I take a 99 crown victoria
engine and put it in a 03 grand
marquis body will the computer
system match up together without a

2 Answers


I would check the two engines share the same torque converter design and rating, also some changes would have to be made to the PCM programming. You would have to keep the 2003 GM's PCM as there are some differences in transmission design between 99 and 03, and the older PCM would not work. If the 99 CV is a police model there are many other issues to address as well.

1 people found this helpful.

I have A 90 grand Marquis I would like to swap it over to a 5.3 engine Anyone have any suggestions on what I would have to do

5 people found this helpful.

Your Answer:

Grand Marquis

Looking for a Used Grand Marquis in your area?

CarGurus has 568 nationwide Grand Marquis listings starting at $1,599.


Sell Your Car Yourself

With a simple, secure transaction.

2003 Mercury Grand Marquis GS

I have a different car

Mercury Grand Marquis Experts

  • #1
    Tracy Hooks
  • #2
  • #3
View All

Find great deals from top-rated dealersTM


Related Models For Sale

Used Lincoln Town Car
24 Great Deals out of 725 listings starting at $2,000
Used Ford Crown Victoria
291 listings starting at $1,795
Used Ford F-150
2,698 Great Deals out of 128,512 listings starting at $1,600
Used Chevrolet Impala
346 Great Deals out of 11,678 listings starting at $1,200
Used Mercury Marauder
24 listings
Used Chevrolet Tahoe
627 Great Deals out of 21,935 listings starting at $1,950
Used Chevrolet Silverado 1500
1,784 Great Deals out of 92,438 listings starting at $2,495
Used Toyota Camry
1,069 Great Deals out of 59,387 listings starting at $1,490
Used Chevrolet Camaro
412 Great Deals out of 14,927 listings starting at $2,950
Used Ford Mustang
516 Great Deals out of 26,051 listings starting at $1,600
Used Lincoln Continental
67 Great Deals out of 2,516 listings starting at $10,995

Used Cars For Sale

2007 Mercury Grand Marquis GS For Sale
9 listings starting at $2,395

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.