Olds 455 buildup
Most of the parts will transfer from one engine to the other. being a taller block, any accessory that bolts to the block and to the head will not fit. Either motor mounts will work, but it is worth knowing the 455 mounts sit the engine slightly lower in the chassis. Internally most parts will exchange between the engines. Cam, timing gear set, distributer, oil pan, lifters (if the 455 is not a toronado) heads (more later), rocker arms. In some cases the 455 exhaust will not fit of the small block. It will hit the oil filter mount and not seal properly. You should use the larger 455 units if not going to headers.
Back to the heads. I mention this only because the 350 heads have smaller combustion chambers. the 350 #5 heads have a 65cc where the 455 C casting is at least 80 and averages 83cc. Given the smaller chamber is worth the effort(new piston are usually much cheaper) the ports on the 350 heads can be ported to equal the 455 heads in port size. The material is there to support a 2.1 int and 1.7 ex. after unshrouding the valve you will have a 68-69cc chamber (F) head. You will find with the larger valve that the ridge under the valve can be cleaned and the port will flow much better. 300+cfm. The exhaust is slightly smaller on some heads as well. Though in your favor. you can also shave .080 from the #5and .100 from the "C" if you want to get really serious. I have 51.5cc on a set of heads. As I mentioned pistons are cheaper though. And a LOT less work. Rocker mounting is identical between the two heads as well. Unless you have tapped to a larger stud? It will bolt up with pushrod changes. The cam is on the small side for a 455 olds. it will do well for you. but it may not appear to "wake up" it will just motor along. the engine likes cam. set the cam center to 2 deg retard for a grunter with this cam. Since this is getting long I will close here. The final note is the carb. While it is will sized for a chevy, it is a little small even for the 350. The 455 like most stroker motors likes a LOT of carb. a 750 is a bottom end carb. you will see improvement all the way up to the predator range of 900cfm on a semi stock 455.