I have a 67 convertible 400 that recently had the engine pulled and underwent a complete engine compartment restoration. I was provided with several sets of numbers. Front of block 29P283725 0635918XH Rear of block 9790071 C219 Head cast 670 The VIN 223677U106739 I have been told that the engine was rebuilt using aftermarket releifed pistons. Aftermarket valve springs and screw in studs are installed. The mechanic estimated the compression at 9 to 1. Factory specs on the 670 should be 10.75 to 1. I'm scheduled to have the car Dynoed on 1/18. If the dyno results show less than expected numbers (330 HP) what steps should I take to get the engine back to it's potential?
