Don't have a book with numbers here, best I could tell you is measure the stroke, then look up the engine specs. The 429 has a shorter stroke then the 460.. The DOVE C heads are not the best, but still plenty good for a stock pickup especially seeing as how you want to run regular gas the compression should be low enough to make it ok. Again, once we know which engine it is for sure there are specs to tell you your compression ratio.

As for the rebuild, a good bore and hone, hypereutectic pistons, quality rings and bearing and a 3 angle valve job should do just fine... Is the intake a square bore or spread bore? If it's a square bore, use it. If it's a spread bore you can still use it but you would need an adapter (Edelbrock makes a nice one) to run a square bore Holley or Edelbrock carb. Stay with something mild on the cam. You would probably want a hydraulic flat tappet cam that is rated for making horsepower from idle to 5,000 RPM. When you pick a cam, get a high quality double roller timing chain and gear set, too. The stock Duraspark ignition should also be fine for street usage. A set of block hugger or long tube headers would be nice, ceramic coated for longevity. They cost more but IMO are worth it. They look 100% better then plain headers with chipped and burnt header paint and rust showing. Finish the exhaust system with a set of 2 1/2" pipes and a good pair of turbo mufflers. Should run strong and look great.