I am trying to build up a 454 engine (first time builder)for my 68 chevelle (TH 400 Trans, 12 bolt GM posi 3:55 gears). The engine is a 4 bolt main, about a 1985 era with peanut port heads, that is supposed to have very low milage, no overbore (it came from a mobile home that caught fire). The engine is in the car now and runs great stock. The car will be an occasional spring summer weekly driver (A&W plus a Sunday cruise) and hopefully compete in a street car shoot out at the drags once a year(about eight 1/4 mile passes per year- just fun, don't care if I win). I am hoping to build a reliable engine about 425 HP/ 500lb/ft torque with high 12's-1/4 mile performance.
I am building from the heads on out. I have a set of 049 casting heads, resurfaced, 110cc chamber, valves enlarged to 2.19" intake, 1.88 " exhaust bowl blended they will have the best spring ,valve roller rocker combo I can buy.
My Questions are as follows:
1. I will keep the stock crank (cast) and rods (cast)with new ARP rod bolts installed (and rods resized).Keeping in mind the cars use, will the stock cast pistons still be OK or do I need to upgrade to hypereutectics (my next choice- likely speed pro) or forged pistons (likely TRW).
2. I have a 750 vacuum secondary Holley (3310). I am thinking of buying a Performer RPM intake but came a cross a GM aluminum dual plane (oval port)from a 502 crate engine that I like. Will the GM intake be a large step down in performance verses the RPM.
3. Cam selection- I am clueless on cams. I have power brakes. Any idea on good cams? I am thinking on the high side of a)(comp cam) -about .544" intake/exhaust lift, 230 deg @0.050, 110 deg lobe separation on the low side b) (comp cam)about .520" intake exhaust lift, 226 deg.@0.050, 110 deg separation. c (PAW cam) about .520" inake/.550 exhaust lift, 230 deg. @0.050. 114 deg. lobe separation. Will a) and c)work with power brakes and be OK for the street. Edelbrock has suggested their performer RPM cam- about .550 lift, 244 deg @0.050- they say I will have enough vacuum for my power brake- this suprises me.

Any suggestion to any of the above questions will be appreciated

Cast crank will be fine,and for what you're doing,cast pistons will work.Your compression will probably be about 8.5 to 1
The GM oval port intake is almost identical to the RPM,so if the price is right,I'd grab it.
I'd use the same hydraulic cam in my combo,its orginally an Ultradyne,but Lunati grinds it now.
Specs are 223/231 @ .050
.525/.550
112 LSA
Power brakes/vacuum works fine.
If you can afford it,the Speed Pro .100 dome hypers would be perfect and get you up to about 9.0 to 1 or so with 110 CC heads.

Thanks for the good info- Mr 4 speed -have a Merry Christmas. Cheers Caplin