355 circle track engine problems
I race a 355 chevy circle track pro stock. I rebuilt the engine at the beginning of the race season. The first time out we finished 6th with the car and no problems. The next three times we had to load her up and bring her home before the feature. My son tells me that if he just eases into the throttle the engine seems fine but if he floors it the engine seems to vibrate like an asphalt roller with the drums on vibrate. I can't distinquish if it is electrical or fuel. We have replaced distributor and all components, coil, wires, carb. Compression is 150 therabouts. Any ideas???