need some help trying to sort out heads 241 vs 243s

[Munzy112]

hi guys I know this topic has most likely been talked about alot. I have a hsv wk grange with 4into 1s with 2.5 all the way through running a 4l60e and 3.9s with a tru track in the rear and a 4k stally im looking at doing cam upgrade aswell as ls7 lifters and upgraded hi flow mellings oil pump and push rods and cam chain all that jazz. I just wondering i will be running a fair size cam package from vcm a vcm710 aswell as otr. My issue is do I go 241 heads and get them cnc or do I go to the 243s cnc is the power diffrence much very interested on your guys opinions thanks. I have attached a photo with the cam specs just not sure how much comp I can go before **** starts hitting lol any help would be great.

 

[07GTS]

if they are both going to be cnc'd then id say the difference wont be much, but if one has bigger valves then id go with which ever that one is to help the cam out in the top end

 

[Munzy112]

I have done abit of reading i know the 243 heads have better flow as the ports on them are different im just unsure how much performance wise the diffrence is and how much im able to deck the heads and unsure about the valves as its my first time doing a rebuild was going to leave the bottom end as is and do head work cam and the oil pump trunions and all the other cam stuff springs ect just leave bottom end as is as I've heard that the bottom ends are strong as