SBC build ???
New here been doing a bunch of research on here and find lots of great info. But the more I learn the more I think I am starting to over think things.
I am looking at building a engine that is not a kit. The block I am using would be a 86+ sbc with a stock bottom end decked to 9.000" and bored .030 over. The plan is to use factory vortec heads with beehive springs and maybe 1.6 roller rockers or 1.5, 5.7 rods ( stock ), inverted dome 4 valve reliefs 10cc hypereutectic pistons, and I am still throwing around which cam to use but it is going to be a hydraulic roller and a .040 head gasket. That should give me a 9.84:1 cr static.
My confusion is on the cam selection when determining the dynamic ration and cracking pressure. If I was to use a comp XR252HR grind I would have a dcr of 8.55:1 with a pressure of 173 psi. If I go with a XR264HR I end up with 8.27:1 dcr and 166 psi. I also thought about going with a XR270HR to end up with dcr 8.09:1 and 161 psi. all of this numbers based off of 1.5 rockers.
I goal is to run this in a 83 k20 pickup truck stock tires size ( 265/75/16 ) and 4.10 gearing mated to a 700r4. and use pump gas 91 at most and if I could get away with 87 then run with that.
What I dont quite understand is the effects of dynamic ratio when determining octane selection and the pressure for low end response.