joyridin Is it worth rebuilding, ONLY the machinist can aswer your question. If you are thinking of using this motor, tear it down and send out the block for cooking, cleaning and sonic check. This is also a heavy motor. If you are going to put it in the cobra, I good set of aluminum heads and intake would be a wise choise and save about 110 pounds on the nose. I nice middle of the road hydro roller valvetrain. Look for some buildups on the 429-460 block for
oil modes. Not more than 10.0 compression and you can run it in reg gas. I am not 100% sure but thought that some years the blocks where thinner walled than other years. We ran a SCJ429 car for couple of years until blowning out the side of the block and went to a 460 short block. got many years until John was killed in the car racing. Map out a buildup and bring it here. We can give you a good idea about HP and torque. A set of Kaase head would really wake up this motor. Not sure of the price on them. You can also get a set of Edelbrocks and have them ported and flowed. The suspension will need to be increased for added weight. Good luck with the build. Limit the rpms to 6,200. this will give you many years of motor without heavy wear. We turned 6,700 on a limiter and got 3 years of racing before breakage. Find max HP and limit the rpms to only 500 rpms over this limit. You are just killing the motor running it higher. Rick L.