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96-98 Modular Motor install into a 91 Fox body 4cyl. Mustang


New Member
Checking in to see if I can get some advice on this Conversion.

91 Mustang 4 cylinder: Installing a 96-98 4.6 4v

Some items I'm using in this conversion.
- Electromotive TEC3r ECU.
- New Aeromotive A1000 Stealth Fuel System
- Digital Dashboard - not purchase yet.

Can I use the original Fox body Dash harness, interior harnesses and front & rear light harnesses? I purchased a 96-98 cobra ECU harness, (even though I'm using an aftermarket ECU) and a 96-98 cobra engine harness. Currently, I noticed that there's three interior Fox body electrical connectors on the passenger side that don't connect to the 96-98 cobra ECU harness. Any advice on this conversion I'd appreciate.


Well-Known Member
Staff member
Welcome to the party. You will enjoy that 4v in a 91 chassis. They are fun to drive and a great deal of attention at shows and gatherings. I'm not an electrical guy, so can't help much with that. There are a number of builders on here that seem to know the electrical side pretty well. Start build thread and post up pictures of your build. Enjoy the site and make yourself at home. The site is not as buys as it used to be, but there are always builders lurking and a lot of good resources on here.


Well-Known Member
Cool project. I ran my 4v in my car and kept all of the fox harnesses. Dash, interior, head/taillights, wipers, horn etc.
The engine and transmission (mine is an auto) and fuel pump were all powered and fused separately.
My car is a 79, so i think it is electrically simpler than your 91.
I also went to Holley EFI. If you can swing it, i recommend the Holley as it is super easy to install, comes with everything needed, and lots of support.
Do you have any pics? Is the motor mostly stock?