Brazing is plenty strong, all the old time and even current SCCA race cars are brazed. Aircraft are brazed. Bicycles made with preposterously thin 4130 are brazed. S/F....Ken M
"Always avoid brazing 4130 steel. The reason to not braze chromemoly is that this steel has a definite grain structure that actually opens up at medium red brazing temperatures. When brazing alloy is melted onto the steel surface, it flows easily into the many small cracks and crevices in the chromemoly steel. Then, as the braze joint cools, the brass will not compress and it forces major cracks to form in the 4130 steel. Often, a brazed 4130 steel part will crack completely in two before your eyes as it cools."
Performance Welding, Richard Finch, c. 1997, pg. 130.
The only place SiBR is typically used on a race car today is putting sheet metal in and header flanges.
Aircraft were brazed - 100 years ago. Then TIG was invented. Some hobby planes may still be.
Conversation was stainless headers. Burns has some great header construction articles.
