First thing to do is get the block, crank, rods, and heads and take to a machine shop of your choice. Have the all of the cylinders checked for roundness and piston to wall clearance. Check with your machinist about an engine rebuild kit with pistons that will give you about 9.0 compression ratio. Depends on how much work the crank and rods need (get an estimate) it might be cheaper to buy a complete rotating assembly. Eagle B18201 BB Chevy 454 Street and Strip Balanced Rotating Assembly - 9.1:1 Keith Black Dome Pistons - BB Chevy 454 Kits - Rotating Assemblies - New - Engine Components | CNC Motorsports | Car Parts | Truck Parts | Competition Engines. If the crank and rods are ok you can get a rebuild kit with 12cc domed pistons for around $500-$600. The heads will have to be checked for hardened seats, valve guides, if they have the small valves I would replace them with 2.19/1.88 valves. There is no way to use a used camshaft. Most engine builders will have you sign a waiver of responsibility if you don't use a roller camshaft. Big blocks are famous for eating lobes on hyd. flat tappet camshafts.

 

First thing to do is get the block, crank, rods, and heads and take to a machine shop of your choice. Have the all of the cylinders checked for roundness and piston to wall clearance. Check with your machinist about an engine rebuild kit with pistons that will give you about 9.0 compression ratio. Depends on how much work the crank and rods need (get an estimate) it might be cheaper to buy a complete rotating assembly. Eagle B18201 BB Chevy 454 Street and Strip Balanced Rotating Assembly - 9.1:1 Keith Black Dome Pistons - BB Chevy 454 Kits - Rotating Assemblies - New - Engine Components | CNC Motorsports | Car Parts | Truck Parts | Competition Engines. If the crank and rods are ok you can get a rebuild kit with 12cc domed pistons for around $500-$600. The heads will have to be checked for hardened seats, valve guides, if they have the small valves I would replace them with 2.19/1.88 valves. There is no way to use a used camshaft. Most engine builders will have you sign a waiver of responsibility if you don't use a roller camshaft. Big blocks are famous for eating lobes on hyd. flat tappet camshafts.

I don't have my list of bbc heads handy,but if those heads are the tiny version of oval ports that came with the rv motor I wouldn't waste a lot of money putting big valves in them,the port and bowl work required is going to be pricey.
Find a better set of oval ports that are worth putting money into,your machinist will tell you which ones to look for depending on how its going to be used.
As far as the camshaft theres plenty of really healthy rat motors running hydraulic flat tappet cams without issue.
Id say your biggest issue will be finding a short enough intake to clear the vette hood.I may have a factory Ls6 intake that I can measure to get you an idea on the height to look for .They were made to work with rect port heads,youll need an oval port version .

 

you will need a hood,BB 1/2 shafts and a TKO-600 transmission. Check the trailing arms very closely as the factory spot welds fail and a fresh 454 will stress every part in the car. The 781 heads are great for over 500 hp. Welcome to "corvette world" where everybody sneers at you except the other corvette guys,,,

 

And I sure hope you have deep pockets as everything on a Vette is $$$$$$$$. I picked my 76 up a couple of years ago for a decent price and it is nothing but a money pit but it gets a lot of looks and compliments and it's nowhere close to being done.

 

zmzx? did you read my post? and a roller cam is almost a must

 

Some people are just hardheaded or they just have to try to make us look like fools. But in the end they will learn and I hope they have deep pockets. IrishMix don't worry about your heads they are the 781's which are one of the best large oval port heads. Your machinist will tell you what will have to be done.