I put a crane energizer 272H cam in my 350 from a 74 nova. The only valvetrain mods are the cam, lifters, and new timing chain. I dont need different valvesprings or anything, do I? The gross lift is .454 .

Depending on the miliage of yours, are they stock? if so I`d recommend new ones that match your cam, back to back dyno tests from stock springs to correct ones showed a 33 horse power increase past 3500 rpm. I`ve run big cams without changing springs and got away with it for a while, until i broke a spring. I added new springs matched to my cam and the increase in power was real noticeable.

your stock springs are good up to about .470", but if you have a lot of miles on them, replace with Z-28 replacement springs, they are cheap insurance.

there is 84000 miles on the engine and through the disassembly it has all looked very good, and the lift is under .470 so I can probably stay with the stock ones, but how much would new ones cost?

I think I payed $50 installed on the heads.