When I was messing with my exhaust the other night, I noticed my driveshaft moved when I pulled on the tailpipe...the trans mount is totally shot. Now I'm thinking about making my custom crossmember for the F150 ES poly mount sooner rather than later.
I did some digging and determined the crossmembers for 4.2L 97 F150s were the same for the 4R70W and M5R2 (supposedly this is not the case with AOD and M5R2 crossmembers used in OBS F150s, those are different). Both auto and manual trucks use the same mount too, but my M5R2 also had a big bracket with what look like vibration dampers that was bolted between the trans mount and the transmission. I'm not sure if 4R70 F150s had that, or if there's any benefit to using the bracket/dampers in my swap. I will need to figure this out to calculate the length to section out of my crossmember, though.
If both the 4R70 and M5R2 f150s used it, then I can ignore the thickness of the bracket. However, if the bracket was only on M5R2 trucks, I need to treat it as a spacer and take the height into consideration when chopping out the difference between the F150 and 5.0 Explorer 4R70W mount (which does not employ a similar bracket/damper). I haven't been able to find good pictures online, so I'm hoping someone can confirm one way or the other. If not, I may just need to go crawl under some 4.2 F150s at the salvage yard to find out for sure.