I'm up to mocking up the engine install in my 54. The front is a 2003-up Crown Vic and the engine is a 4.6 out of a Mark VIII. I removed the front engine crossmember to get the front suspension in. The rear mount is still there.

The question is how to deal with the original rear engine crossmember in my engine install.

Without removing the rear engine crossmember, I will have to raise the engine about 4" for the trans pan to clear the old crossmember. Is that crossmember necessary? Raising the engine helps with oil filter clearance, but I'm afraid extending the mounts will introduce some potential motion and other problems. The trans hump in the cab will be OK.

If I remove the crossmember, I can mount the engine on the CV crossmember where it belongs with stock mounts. The pinion angle to the rear is better also. Question is whether more support is needed. There would be the original radiator mount, the IFS crossmember and the trans crossmember and then the stock members further back. By the way, the front frame is boxed back to the firewall.

 

How about using a newer pickup transmission cross member? and install that like 80-96 F150.
I'd like to see how all this goes together for you. I thought Mark VIII drivetrain and CV front is a good combo.
How do the tires fit in the front fenders?

 

You can get a right angle or a remote oil filter relocation kit to relieve the interference. If you are talking about the stock crossmember at the rear spring mount, you could move it back to use as a rear tranny mount, or cut the center out of it and add a dropped center, or just elininate it and replace it with the tranny mount. If you replace it, be sure the tranny mount is built so it prevents the frame from being able to lay over or move apart. The last one would be my choice.