Hi, am putting together a mild B20B for my Australian 72 142. Current specs are rebuilt bottom end with 40thou oversize pistons, street performance cam, IPD followers and tubular pushrods, mildly ported exhaust ports, later f/i inlet valves and a little unshrouding, head milled to create 10.5:1 CR of b20E, good rockers and new rocker shaft, later f/i exhaust manifold and twin 40mm dellorto's(yet to be sorted). My question before it all goes together is will I require dual or beehive valve springs or will stockers suffice(it will get some hard use but mostly a street driver).

Cheers in advance!