Sierra6.0

so i have a lq4 with the cam unknown i bought the truck how it is it ran good and is now broken basically because it jumped time and ended up dropping a valve the cylinder is scored pretty good and piston broken . basically on a decent budget so i'm going to get a pullout 6.0 lq4 or lq9 and rebuild it anyways hone cylinders new piston rings and all new bearings , but if i can find a lq9 whats the difference besides flat top pistons and how good would it be if i put on 243 heads and if i can only find an lq4 would it be worth getting 243 heads i have a good friend saving them for me to buy . of course the heads will probably need new valves and springs he wants 400 for the set would it be better to just buy some decent ones or rebuild those? gonna swap my cam back into whatever i get but i'm not sure on the specs until i mic it out and ill need the proper head gasket due to clearance. just want opinions from others setups

Sierra6.0

looking to put down hopefully around around 500 or 500+ if obtainable without spray or boost just yet

cookseyb

Drop the 243's or 799's (same head,different casting method) off at Scoggin-Dickey Chevrolet and let them rework them for you. They can spec out a cam for your engine and tune it also...