I Have a pair of 6x heads for my 455,im hoping for mid 450hp,first is that possible with factory 6xs,also is porting them going to make a different,I plan on gasket matching them,but what about massaging the runners?  

Porting them will make a considerable differance I would recomend porting the heads.Also depending on witch 6X heads you have will make a compression ratio increase to tell look for a (4)-(8) OR (11) on the exhuast boss this will tell what CC combustion chambers the heads have.  

They are 8s,i was thinking about having them shaved,i have a .060 455 w/trw 2359s..maybe 9.5to1?
thats what im shooting for,you think mid 400hp is possible?other setup is factory aluminum intake,holley 800 dbl.,cam is 244/252,lobe:114 center:108 .548/.563 hydraulic.(1.6 rockers)just worried bout the valves smashing the pistons,but ill check when its assembled..  

What is the part# on the cam you are using.Also the C.R. will be 9:1.  

Its a H.O.Racing piece: HC-03A The specs are 308/320 Dur. 244/252 @.050 .498/.512 lift with 1.5 rockers(but i have 1.65) Lobe sep:114, Centerline 108  

You should be able to reach your H.P. goal but I think that might be to much lift and may run into a clearance problem.  

Thats what im worried about,im gonna clay it out this weekend,whats the most i can get away with?I have comps.9.136" pushrods,maybe shorter rods?i know the valvetrain in the heart & soul so i'm concentating on that most..probable gonna get stuck getting some 1.5 rockers tho...thanks for your help. -Andrew