57 dodge sierra wagon with engine and trans from 97 ram.

Not sure where to put this so i will start here. I have a motor and trans out of a 97 sst ram. It is still fuel injected. I have developed a miss but only after it shifts into overdrive. It will miss when i lighty ste on the gas. If i put my foot into it it runs fine. I have replaced plugs, wires, throttle position sensor, fuel injectors. Only codes i get are miss fire in almost every cylinder and battery temp sensor which isnt hooked up. I have an aermotive regulator that is set for 51 psi at idle and holds steady as i increase throttle. What am i missing?

If you have a misfire in almost all cylinders then it's something in common.

the injectors all use a common 12V to them and the computer switches the ground on the fuel side. I believe those engines had a plenum leak issue that might be something to look at too.

On the ignition side there is a lot more in common electrically.

I would look in those areas first. Cap, rotor, coil, etc.

Plenum was fixed before we dropped motor in which was about 700 miles ago. I guess i will look at it again. Same with coil. I will rplace cap and rotor just to rule it out. I have a round 10" air clraner on it. Could the engine not be getting enough cold air?

unless the filter is only 1/2" tall or packed full of dirt I doubt that is the problem.

Rereading the problem it looks like it's a high load, minimal throttle situation where it occurs, I'm sorta thinking vacuum leak somewhere. WOT is usually rich anyway, so a vacuum leak doesn't show up as easily then. Generally, I'm thinking the ignition would not be that picky.

Have you done any vacuum leak tests?

Filter is like two inches tall. Never thought of vacuum. I replaced one i had to fuel regulator. Brake booster was fine but i will definitely test it. We never thought of that. Thanks!

According to vacuum gauge im holding steady at just over 16 at idle. I sprayed carb cleaner at every hose end and no difference in idle. On the right side of engine i have fuel regulator and pcv valve and on left side i have brake booster and the other is plugged. Front is plugged too. Plenum looked great.

Got a couple of pics for a fellow '57 Sierra owner?

Not sure how from my phone

Hey mods can this be moved to truck section?