hi guys; i did a search for this question, but didnt come up with much. i have a 1975 454 that was built to 500 + hp. i want to install reproduction deep groove pullies as the 1970 ls-6's were equipped with as opposed to the billet,polished type. a lot of the deep groove pullies seem to be geared toward 396 and 427's with a narrower harmonic balancer. this appears to be the problem with the alignment on my application. a 396 harmonic balancer is about 1 3/8" and the 454 is about 1 11/16. i got reproduction deep groove pullies for all accessories including the crank. the crank is the problem here. does anyone know if they make a reproduction "deep groove" crank pulley for a 454 or was the harmonic balancer a narrower width in 1970 on the ls-6??