Yea those are nice heads. Running the 799's and 4.8 intake will do just fine but like stated above, the edelbrock intake will perform much better in the higher rpms. Your compression ratio will be higher with the 799s vs 823 since the combustion chamber is smaller. Those heads will like the 224 cam. Sounds like a good combo to me

 

You'll make more power with the l92 heads. They also have 2.165 intake valve vs the 2.0 intake valve of the ls6 head. I ran the ls6 heads before and made 380 and now with the l92 heads with a cam for these heads I'm making 455. People say you lose low end with the edelbrock intake. I beg to differ, I pulled a 24' deck boat with a 244/248 cam and had no problem passing cars and going up hills never coming out of overdrive. If your worried about compression, have them milled .030-.040 and have the same compression as the ls6 heads.

 

thanks for your help guys ill start a build thread when it comes time and try to post pictures