I dunno about the upper A-arms, but you might think about going heavier that 1" for the t-bars. I just installed 1" bars on my 74 challenger with a 440 (iron everything) and low profile tires. The ride is not nearly as stiff as I expected. I found my torsion bars new on ebay for like $150. You can probably find them again however, you may want to think about 1.06" bars