I have a low mileage 3V 4.6L from an Explorer that I may want to use in my 97 TBird. It will get PI heads and cams. My concern is what is different and the changes needed. I think the compression will be higher like with the NPI engine, front cover and chain assy. from the TBird can be swapped over. Are the motor mount bolt bosses in the same location? It does have a 6 bolt crank shaft so no problem with the flexplate. What about the head bolt thread depth, same as the TBird block? Thanks for any info.....Ken.