Is 10-15 psi to much?

I recently bought a 62 ford falcon, complete stock upgraded inline 6. With a rebuilt c4 from eagle transmission. There's not to much performance from the inline 6. So I bought a Mexican 74 small block Ford 302. And planned to rebuild it. So I bought a 89 5.0 block with the forged pistons and rods was going to keep the stock cam and crank from the 5.0 block. I was just going to throw everything into the 74 block and drop it into my falcon. Or would it be worth to buy a new cam and a steel crank? As I'm trying to achieve atleast 10 psi. 15 max.

It seems you are taking about adding forced induction to the engine.
Ford crankshafts, rods and pistons are inspected for defects before the engine is built. Stock rods in a Ford engine are the counter part to Chevrolet pink rods.
What you need to pay attention to is compression ratio's. With the performance heads and pistons it is very easy to end up with a compression ratio that is greater then 9.5 to one. Because it is not so simple as just swapping pistons you will need machine shop work. Talk to who ever is going to fit the pistons to the block about what compression ratio you need.
Having owned a few early Falcons and Fairlane's with engines from the I-6 to 289's I would suggest that a mild 5.0 in a Falcon is more then enough for a daily driver. By mild I mean a cam about 270 and believe it or not a big two barrel carburetor.
The difficult thing is if you want to go with a stick. Getting a clutch set up for a hydraulic clutch is the easiest for several reasons. One is the later Windsor blocks don't have the boss for the clutch z-bar pivot that Ford used to use.

The stock rear axle assembly won't survive behind a V8 and the suspension and brakes will need upgrading, too. You will also need a larger radiator to handle the extra heat generated by the V8. Good luck with this. A hot rod 62 Falcon is cool ride.