Been following the forums for a while now and it’s always a big help. I’m at a point of my build now that I’m lost and need some advice!

build is a 351w out of a 1995 F250. Was bored 40 over. New pistons, rods, rings. Stock heads were bathed and tested good. Same push rods, all were straight, new hydraulic roller lifter. Here’s the curve ball. The guy that worked on my engine gave me a cam that he said would work, I put it in not knowing exactly what it was. Upon firing it up first time, four cylinders fired, four did not. Found through FTE that a pre HO 302 cam has that 1-5-4-2-6-3-7-8 firing order and I had the 351 1-3-7-2-6-5-4-8 wired. So I required the firing order, motor fired right off. That’s the only evidence I have that it’s a pre HO 302 cam.

Timing has been difficult as it just doesn’t seem to smooth things out. Pulled the SPOUT, timed to 10*, played with timing, just won’t idle right. Pull the plugs and 1-4 bank is all black, 5-8 seem normal. Did a compression test. 1-4 cylinders are 134-135 psi, 5-8 are in the 150-153 range.

Looking for advice on the next steps I guess in diagnosing why it idles so rough. I mean it shakes the whole damn truck! Seems to be a fueling issue. I also rewired the 3-5 and 4-7 injectors to match the ignition timing order. Not sure if that did anything. Truck has headman headers and 3” back true dual exhaust to some FlowMasters. Only has one o2 sensor in the 1-4 bank. Has EGR open to atmosphere. TAD and TAB are unplugged at the harness but tied into vacuum lines. Also very loud valve train. Pulling the tins today to measure valve movement.

 

Check your other thread for responses….