Auto trans decision help for my new LSx build

[derotoreut]

Hey guys, I am beginning work on my first frame off with LSx install on a 71 SWB. I'm having a custom chassis built by Scott's Hot Rod. I haven't determined my exact engine yet, but I plan to look for a new GM engine/trans package. I decided to go with an automatic transmission and Scott's recommended setting up the chassis for a 4L60e transmission. Can you give me any insight on if this is a good way to go? from what little I know, it sounds like the 4L80e is a stronger transmission, but may be bigger and heavier. What are my options, and what would be a good way to go? Right now I am considering possibly new LS2 or LS3 engine/auto trans combo. Please help me with my auto trans options, so I am able to get the chassis set up properly. I will need to get back with them before they move too far along with fabrication. Thanks.