I think the transmission is the exact same one that goes in the 5.0 and I think the only thing you have to change for it to bolt up is the bellhousing.
The 4 banger T5's input shaft is a little smaller so you'll need a different pilot bearing (Motormite 14672 & Timken 202ff). The gearing is nice on a 4 banger T5 with 3:73 gears it feels like having 4:10's I did plenty of miles and a few trips to the strip and it never let go. 1st gear is useless since it's like a "granny gear" like you'd find on some trucks, great for roasting tires without the need for a line-lock lol.
The 4 banger clutch, flywheel and bellhousing will NOT work obviously. The driveshaft will fit and the 7.5 will have nice gearing (3:55) I don't think it will be a LSD though and it would be wise to find an 8.8 as soon as possible but it's not an "emergency".
The input shaft isn't longer than the V8, if it is it didn't bother anything. I tested the length of the shaft versus the depth of the crank hole and I had lots of play. But if you can get your hands on a V8 tranny; that would be best. My 2.3 tranny was only a temporary solution and I've found the correct transmission now... so the 4 banger T5 is a spare. Of course now I might start looking for some 4:10's