The bar the we supplied is designed for a stock k member. The only aftermarket k member that we offer is the HDK package which uses a completely different design. The bar that we supply would work up to 72 so if the Qa1 arms are based off the 73-76 arm you may be able to use a later bar. The bar that we had supplied had an eye to eye measurement of 45" now the 1973-76 uses and eye to eye measurement of 37 1/4". Hope this info helps you in solving your issue.
Thanks
James