th350 help
th350 help 
http://www.geocities.com/nova442.geo/ls1.html
scroll down to the bottom, the crossmemebr is out of an auto, just welded a tab on the front for the TH350. If you cant weld, you could probably bolt something on, its only relocated by a couple inches off the cossmember and only supports the weight of the tranny.
You'll need a reluctor ring from a 700R4 in place of the speedo gear (one in the sticky is for a TH400 way different dont believe the part numbers up there). And the only tailshaft (short) that the sensor will fit in is from a B.O.P. tranny.
you'll need a longer driveshaft.
And if you buy the TCI SFI approved flexplate it comes with the hub adapter so you can use a standard TH350 converter instead of paying a million dollars for one specifically made for an LS1.
scroll down to the bottom, the crossmemebr is out of an auto, just welded a tab on the front for the TH350. If you cant weld, you could probably bolt something on, its only relocated by a couple inches off the cossmember and only supports the weight of the tranny.
You'll need a reluctor ring from a 700R4 in place of the speedo gear (one in the sticky is for a TH400 way different dont believe the part numbers up there). And the only tailshaft (short) that the sensor will fit in is from a B.O.P. tranny.
you'll need a longer driveshaft.
And if you buy the TCI SFI approved flexplate it comes with the hub adapter so you can use a standard TH350 converter instead of paying a million dollars for one specifically made for an LS1.