The 4L60E also has alot of "upgrade" parts available for it but it would need a controller (I'
m pretty sure the 4L30E's electronics would not interchange) but also the Atlas engine family does NOT use the same bolt pattern, it looks similar to the 60 degree pattern but it is not. So the H3 trans won't just bolt up to our engines. Here's a pic of an Atlas bellhousing next to a small block chevy pattern, the 60 degree pattern is actually different than both:



You could get a 700R4 from behind an early 2.8 V6 S10 and mod that to work (a guy on the Planet used a Dana 300 case or people have made adapters to keep the Zu' case).