What casting no. are you talking about. There are many, oval, peanut or several versions of rectangular.

 

I have 390 casting they have been ported, bowl work, 2.19/1.88 valves and chamber work

 

600hp needs at least 300cfm on the intake.

In general, stock bbc heads with 2.19" valves flow about 250 cfm on the intake at 0.500", maybe 260 cfm at 0.600. You would need some good really porting to get to 300 cfm.

 

How much compression are you trying to put in it....those heads have a 97cc chamber

 

Compression I am wanting is anywhere from 10.5 to 12.5

 

If you are looking to build a 12.5:1 496 you aren't going to be happy with those heads.

 

Will 11 be good and what would go wrong with 12.5 with these heads just curious this is my first big block build

 

I guess what I am trying to say is that the potential of a high compression 496 will be limited with closed chamber oval port heads.I would get some aftermarket heads.If you were doing a 9:1 cruiser it might be a different story.

 

Oh okay it's not a daily driver more like street and strip will drive on on the street once a week and not really worried bout the gas I was planning on mixing it. What do u think about the 049 casting because I am looking to make 600 plus torque and close to 600 hp or do u still recommend aftermarket heads

 

I think F-Bird posted a link a while back to a 396 in a Nova with 10.5:1 that made 550 with closed ovals on pump gas so a 496 with 049 should hit 600 easily.........but if you do a solid roller engine with aluminum heads you'd be smokin........with that many cubes you can put a healthy cam in it and still be streetable.Why stop at 600 if you are going to the trouble of building a 496?...do you have pistons already?

 

not tryi nto hgih jack this threat but i have a question im doing a 496 bbc D/D what kind of power con i expect with 049s or 781, im thinkin abotu running a 9-1 or 9.5-1 engine

 

I think F-Bird posted a link a while back to a 396 in a Nova with 10.5:1 that made 550 with closed ovals on pump gas so a 496 with 049 should hit 600 easily.........but if you do a solid roller engine with aluminum heads you'd be smokin........with that many cubes you can put a healthy cam in it and still be streetable.Why stop at 600 if you are going to the trouble of building a 496?...do you have pistons already?

later in the future I will get some aftermarket heads so for now will the 049 be a better choice in making it to the 600 mark than the 390 and no I don't have the pistons yet I am going solid roller don't no which one to choose I know I'm going to need a big one I am open to any suggestions