468 going together, need some advice

[BossHogg69]

I'll start out with a few details on my build. I have a shortstep '69 C10, that has a TKO-500 (3.27 1st gear) and 3.73's out back. I pulled the 454 out to wring a little more hp from it and here's what I'm using top to bottom:

Holley 870 Street Avenger
E'brock RPM-O Air Gap (port matched to heads), 1" open spacer
E'brock RPM Marine Oval Port heads, 290cc intake, 110cc chamber with 2.25" intakes, 1.89" exhaust valves, bowl blended and gasket matched.
Crower valvesprings (68340-16), 10* locks, retainers
Comp Magnum pushrods
Comp flat tappet lifters
Crane full roller rockers 1.7:1
Cloyes Hex-a-Just Billet steel true roller, Cloyes Quick Buttom timing cover
SRP 212136 pistons, .060" over, -23cc dome
GM 'truck' rods, ARP bolts
GM cast crank
GM 2 bolt block, ARP studs, piston will be sitting .010" in the hole.

Now, during my parts hoarding phase (the past year) I picked up two different cams along the way - one is an Extreme Energy 4x4 278, #11-243-4.
http://compcams.com/Cam_Specs/CamDet...?csid=402&sb=0

The other is this one - http://compcams.com/Cam_Specs/CamDet...?csid=398&sb=0 a XE294 #11-254-4

Now, I know I'll get the 'just go hydraulic roller' and I'm not interested in that, my money is spent, and heavy hydraulic roller lifters in a BB with 2.25" valves is good for valve float after about 5500rpm. I'd like to have a solid roller, but I'm not interested in running valves at all. I am however interested in making some good midrange with a decent top end charge. I'm having the motor built for 10.8:1 CR with a .039" head gasket (tentative). The heads' deck surfaces have been cleaned up, and I expect the chambers to cc out @ about 108-109. I've been looking into the effects of the bigger cam on my dynamic compression ratio (the one that means the most) and the 294 will be down compared to the 278 cam (8.0:1 vs 8.5:1), but I'm wondering if the bigger cam will make up for this through the midrange and top end? I know you've all seen/read different builds online like this http://www.carcraft.com/techarticles...evy/index.html. I will be disappointed if I don't get 550hp and 570lb-ft out of this thing if I use the 294 cam, but does anyone think I might be better off with the 278? Naturally I want this thing to have a hard hitting idle (who doesn't), but I want to be able to walk the walk, not just put the biggest cam in there and have mismatched combo. This will be a street/strip/toy btw...

Sorry for the forever long post, I just want to get all the info out there.