I run everything though the balance shop, as things stand now you have no way of knowing if the rotatating assembly sans damper and flywheel can be balanced with the damper and flywheel you have or with anyother for that matter. The whole assembly has to be balanced in that the rods and pistons equalized to each other, then spun with the damper and flywheel to determine where on the crank, damper and flywheel adjustments need to be made. Never, ever trust the balance from these kits and don't buy them as balanced they often don't come close making that extra cost a total waste of your money. Buy the pieces install and check clearances as often you have to grind on the rods and pistons with these stroker kits, check the valve to piston clearance as that may require grinding on the piston. Then take it apart and send all the pieces damper and fly/flex even if they are supposed to be neutral balanced they often aren't.Just had built a 383 stroker
GM 1 piece rear main seal block
Eagle Rotating assembly kit (4.030X3.750 5.7 Rod, -18CC inverted dome) PN: Eagle B13004L Eagle Street and Strip Rotating Assembly
The kit came with everything including harmonic balancer and flex plate. I didnt need the flex plate because the transmission is 4 speed manual.
I used flexplate JEGS Performance Products 601250 JEGS Flywheels
Its a 153 tooth external balance flexplate for 350 chevy 1 piece rear main.
I now have severe engine vibration and gets worse as RPM increases.....