no spark at plugs

i have an 85 gmc that will not start. we had to replace engine due to a broken crank on the 305. we replaced engine with a 350 but now it will not start.we have replaced the coil,dist cap,rotor and even tried another distributor.pulled no one plug and put it in wire and we have no spark.there is 12v going into distr and 9v while cranking.any help would be appreciated.

Make sure your distribitor is connected to the Electonic Spark Control. Look for 4 wires and a harness that goes to the firewall. You will not have spark is this harness is disconnected.

You may also overide the ESC by disconnecting the distribitor from the ESC (Electronic Spark Control).Then on the wires that go to the distribitor run a 14 guage jumper wire across the "A" and "C" terminal. If this gives you spark, then the ESC is shot. I would then suggest buying a four pin Distribitor. You may find them new on EBay for about $90 bucks if your parts store is asking for 150-200 bucks.

you were right.i wired around esc and now have spark. thanks for your help