The 428 wil fit, unless your shock towers have "leaned" in toward each other due to stress and age. The big block cars did have extra reinforcemnets at the bottoms of them. After dealing with headers with an FE ( or other big blocks) you won't be as enthusiastic about them as you now are. I would highly recommend getting a set of FPA Tri-Y headers for it instead of the Hooker/Hedman 4 into 1's, they're easier to live with but a little pricier at around $400 a set. Also recommmend a good assortment of 3/8 or 7/16 end wrenches( for whichever head size bolts you use, I'd go with 3/8ths) for those header bolts, you'll definately need them, plus a butt-load of patience to install the header bolts.And don't EVEN think of trying to use allen head bolts, they won't work. It used to take me 3 hours just to install all the bolts on my 390 and later the 427