Since you are rebuilding the engine, do it right or you will be sorry later. Have the block boiled and tested for cracks. Bore the cylinders. New cam bearings, main & rod bearings. Grind the crank. New pistons and rings. If you can come up with the scratch, have the crank and pistons balanced. Convert the block to full flow filter. New cam and lifters, call Patricks about them. I know the vette used a 261 cam, don't know about the lifters.
For the head, the 848 head is probably the best due to its higher compression ratio. Have it magnafluxed or pressure tested. New valve springs and keepers. Have the machining done for hardened valve seats and umbrella style valve seals.
You really need a split exhaust and more intake anc carb to take advantage of the cam, but they can be added later.
