first off thanks for taking the time to look over my thread.

ive got a 85 305 w/ 416 heads in my iroc i plan to swap in a 383 when i finally get it finished, which will prob be at least a year or so off. so in the mean time id like to pep up the 305 w some parts ive got around the shop. im basically wanting to know if the performance gain will be. ok well heres the list of things ive got laying around.
1. comp 270 magnum cam 220 @ .50 w 470 lift
2. complete mallory ign set up w/ mag. breakerless dist, coil, hyfire 6A box
3. holly 650 quad replacement w/ vac secondaries and elec choke
4. shorty headers w/ y pipe

the car already has a weiand intake on it, it is a 5 speed car w/ 3.73s out back. i know the 270 cam is popular for 350s but how will it do in a smaller 305? will stock heads support this cam with a valve spring swap? ive come across a little info about exhaust springs having rotators? and the valve guide bosses needing to be cut down w/ high lift cams? i need some imput on this!! Id like to say that im not trying to build some badass 305 im was just thinking i could have a little fun w/ the 305 before shes pulled. i have all these parts already so cost would be limited to gaskets, lifters, valve seals and springs. thanks guys Mark