i currently have a 700r4 in my 95Z28, tranny puked and i was entertaining the idea of a th350 or 400, the car is a 355 and currently runs into the 11's and im doing more this winter to nudge it into the mid to low 10's so im gonna need the added strength. how much more work is it to get a th350 or 400 in my car?

 

new converter
158-tooth flywheel
modified transmission x-member
longer driveshaft
new dipstick
speedo sensor & reluctor from '91 454 SS truck (if you keep factory speedometer)
new shifter (or modify stock to work w/ 3-spd)
ECM reprogrammed to M6 transmission

I'm sure there's more, but it's been so long since I did my swap.

 

If you use a 9 inch tailshaft TH350 then you can use the stock length driveshaft.
Dakota digital has a speedo fix thats pretty cheap.
Mount up an aftermarket shifter, I went with a Pro Stick.
BMR and Spohn offer tranny crossmembers for this swap and BMR even has one that will let you keep your adjustable TA (like I have) the TA mounts to the tranny crossmember.
It can be a little expensive but a monster built 700R4 or 60E will cost more.
An added bonus is a TH400 is 28 lbs lighter than the 60E, even more for a TH350.
You lose OD but I would not want to drive my 10 second car everyday anyway.