I am looking to see what needs to be modified for the old style sbc/bbc ultra bell to be bolted up to a LS1. What hardware was used and what had to be modified to the bell housing and or engine.? Pics and information is much appreciated. I do know there is a new style ultra bell that is LS specific , thanks fellas

 

No Modification required.

The only change, is that one bolt hole in the bell-housing can not be used because the engine does not contain the needed hole.
The upper-most right (Vehicle passenger side) bolt hole in the bell-housing will go unused.

However if the bell-housing purchased has a bolt hole at the 12 O'clock position... It can be used.

 

The ultrabell is just a stronger version of a stock bell.

So do all of the normal modifications you would do with a stock bell th400. Use a crank adapter and a flexplate to match the converter. The rest is easy peasey