If you look on Rubber the Right Way website or the online marketplace you can get cheater taller stock appearing valve covers in chrome or raw/painted. I have ran G-Force crossmembers with 3 and 3.5 inch exhaust and big block Chevy hearts and the Hooker 2455 and 2241 headers. I have also used the Iceman crossmembers with the big exhaust and headers. Some guys have used Crown Vic crossmembers, I do not have direct firsthand knowledge of years or fitment. I have cut down B-body earlier Impala crossmembers in years past, but, at that time we only ran 2.5 inch exhaust (that's all we had).
I will see if I can get some pics.
I will see if I can get some pics.