MSD Question please

I have a 1966 Mustang, but have a '93 5.0 EFI Cobra motor in it. Ever since the swap, I can't get it to run right. I am thinking it's the Motorcraft distributor and perhaps a bad TFI on it.

I am going to purchase an MSD distributor. Do I also have to purchase an MSD Ignition box as well?? Or will the MSD distributor be all I need?

Thanks all for the responses.

Liljoe - not sure where to start. Upgrades on motor are underdrive pullys, b303, PI 2600 stall, cold air and a tune chip.

Issue is since the swap - it just won't stay running. We have verified spark and fuel is good. The MAF and IAC is good. Getting good but pulsating voltage to the coil. When checking timing, it's bouncing on me a bit.

I can drive the car cold with the 'snout connector' unplug and it does 'ok'. When it warms up, it gets worse. If I try to drive it with the snout connected, it's very difficult to keep it running.

Verified all the basics. I am hoping with a new distributor and the new TFI as well that it will resolve a lot of the problems.

I am not one for throwing parts at a problem either. However right now...I am totally out of ideas and getting frustrated.

Thanks again.

I have no codes, except for EGR but that's because I deleted that in my swap.