i need help w/duster engine

ok now.. rollers are cool.. and yea u got it right.. mmmm u will be able to have a more agressive ramp on the cam, this will increase the time the inntake is open fully.. read tech on cams at huges.. mm anyways u wont bugger to worry of the valves hitting the pistons.. cus the higher lift than .550 will just hurt the flow rate.. just for an example http://www.shadydellspeedshop.com/jhead.htm .. now i flowed far worse on some old ported j-heads of mine.. but after .550 no more.. u will be bugged with the need of stronger springs when the agressive lift ramp will make the speed of the mass (valves, pushrods, locks and retainers) and could easily make valvefloat... the thing u have got right.. the increased valve speed and more open time (time with valves fully opened) will give ur heads more potential.. u may also add cuple of cc to ur plenum.. (spacer of some sort)