Hi all im looking for advice on my first engine build. i recently picked up a mark4 454 block at a swap meet and plan on throwing it in my 99 suburban. im looking for 500 plus hp and 500 plus ftlbs. ive never built an engine before from the ground up but i have turned wrenches my whole life. the engine is a 2 bolt main so i know i will be limited that way but i have pondered the idea of adding the 4 bolt for extra security.
My plans so far are
boring 30 over not sure if i want 4 or 4.25 crank suggestions?
i would really like it to have a fairly aggressive sound but i still need drivability so cam suggestions?
for fueling i will be running one of the self tuning ecus reason for that is i live near dallas at 500ish feet but regularly go to denver area so in my opinion it would work better than a carb
transmission will be a built 4l80e with a standalone controller and dedicated cooler
will be doing the suspension and diffs
long tube headers
dual plane intake
3 core radiator with dual electric fans

other than that im a bit lost. im open to any and all suggestions the vehicle will be used mainly for driving to and from work occasionally hauling a boat or small trailer it will have about a 33 inch tire and some body armor so it will be heavy.

block is a 3963512 casting
heads are 3931063. i know these are 427 heads but will they work for power goals i have a reputable engine builder in my area that can mill them enlarge the valves or what ever. thoughts?

lot im asking but input would be very appreciated thanks.

ps. im not worried about mpg if you cant tell