I just got done installing my newly rebuilt 351W (came out of a '95 F150), and after attempting to start it yesterday there was a very loud backfire. The engine never started and I didn't continue to crank after the backfire. I'm thinking I didn't install the distributor correctly.
I put the #1 cylinder at the top of the compression stroke and the crank positioned at TDC. I got a new MSD TFI distributor and since the cap did not have an indicator for which plug tower is the #1, I thought I would mirror what the stock Fox Body mustang style TFI distributor caps show as the #1 tower (see pic). I have the TFI module positioned at about the 4 o'clock position. My firing order is 13726548. Do I not have the #1 tower on the distributor cap correct? Is the rotation of the distributor rotor supposed to be CCW? A book I have showed the rotation going CW so that's how I set up the wiring, but now as I type this I'm wondering if the rotation is CCW.
Also of note is I have open exhaust at the moment. Didn't know if having open exhaust with the O2 sensors right there at the collector would cause any backfiring issues or any other issues for that matter.