Though they are pretty similar you will find differences in the cases. Some had a longer tail shaft housing so you’ll have to measure. Also I don’t remember what year but around 2000 or so Ford removed the vss from the 4r. Check to see if the sensor is there. If not you can’t use it.
98 gt transmission swap help
4
I am swapping my 98 gt 4r70w automatic transmission. I did my research and learned that only another 98 gt 4r70w automatic transmission would be an easy plug-and-play fit. I took my transmission out and bought a transmission from a guy who owned a shop 4 hours away. The guy told me it's a 100% plug-and-play as it is another 98 gt 4r70w. However, I think it's a Mercury Grand Marquis 4r70w transmission. The wiring harness for the transmission is completely different and when I looked up the numbers located on the wiring harness of the transmission I bought (4w7t-7c078-aa) it came up with a 03-04 Mercury Grand Marquis Town Car Transmission wiring harness. My 98 gt transmission wiring harness is much longer than the supposedly 98 gt transmission wiring harness. My 98 gt's harness is on the right and the one i bought is on the left.
This is a picture of the transmission tag I own. 
This is a picture of the transmission tag I had bought.
This is on the wiring harness of the transmission I had bought and if you look it up it comes up with Mercury Grand Marquis 4r70w transmission.
My question is can this swap still work? Thank you for any help.
My 98 gt's harness is on the right and the one i bought is on the left. This is a picture of the transmission tag I own. This is a picture of the transmission tag I had bought. This is on the wiring harness of the transmission I had bought and if you look it up it comes up with Mercury Grand Marquis 4r70w transmission.My question is can this swap still work? Thank you for any help.
