I am planning on doing the swap but my question is this I have a 97 t-56. from what I have read the 98+ have a dif bolt pattern on the bellhousing. Is this true? and can I use a 98+ bellhousing on my 97 t-56 to bolt to a ls1?

 

The imput shaft is different as well. It can be concerted but you might as well just start off with the correct one.

 

You'd have to change the adapter plate on the trans also, in order to mount the LS1 style slave cylinder/throwout bearing.

For what it would cost, you're probably better off selling it and getting an LS1 trans. There are always people getting LS1 tranny's for their gen1 motors only to find out it won't work....maybe you can find someone who would trade you??