I have a 1969 Corvette Convertible 4 speed with the L46 motor 350/350. What parts would need to be changed if i wanted to put a 427 or 454 motor in this car? The car also has the factory side exhaust.

The entire front suspension package needs to be changed out, especially the springs. Larger radiator also. The transmission will remain the same, but I think the motor mounts might need to be relocated. The drive train is not made for the big motor power. I built my 69 Corvette 350-350 to put out around 450 HP with no modifications to anything other that the motor itself. I put in a 400 crank, bored it out 0.040, large cam, new high flow aluminum heads, long headers, new intake and duel carburetors. transistorized ignition, larger radiator and electric duel fans. New 5 speed transmission. I was faster than the first two new additions of the Z06 Corvette that came back out. There are a lot of articles out about that type of swap, look for them on line. If you do it, do it right and don't compromise on quality parts or you'll be miserable. Good luck, and have fun. Oh yes, the value of your Corvette will drop also. Don't forget you will need a new hood for clearance of the taller engine.