I am building a street/strip '80 Regal and I am planning on building a 370 - 400 hp 350 SBB for power. I will be using a Moser 12bolt rear with 4:56 gears and was planning on using a built 200 R4 with ??? converter that is TBD. Anyhow, outside of a trans cross member change, would I need to do any other chassis bracing or boxing to with this combination? I didn't think so, but I would be interested in hearing back from you all on this. Thanks.
Add additional welding to the rear end lower control arm brackets (frame end). I have been racing "G" body cars for about 15 years and this is the only problem I have ever had.
Thanks for your feedback. There is a decent shop called TNT Racing that sells pre-fab braces for both upper and lower control arm frame mounting locations. A bit expensive, but already fabricated.
You can also tie the rear horns together using some 1" square stock bolted right behind the bumper shocks. Might consider the rear seat braces, and the front end braces as well.
