I have a 1989 E150 Club Wagon with the 351 motor and c6 tranny. I'm replacing leaking seals and want to refresh the engine a bit while I have it torn down. We have emissions testing so I think I have to keep the EGR and cat but am planning on headers of some sort after I get the engine back together. I'm going to install the Crane 444232 cam based on Conanski's recommendation but I'm unsure of how much remaining wiggle room I have as I want to stay with the stock EFI setup. I know the intake and heads don't flow so well which brings me to my question. How much poliishing and/or porting could I get away with on the heads and intake before the PCM couldn't compensate? And is it a fuel delivery issue that limits the PCM? If room is very limited I will just polish out casting defects,etc. Would port matching be too much?I know GT40 heads would be a better solution but there are none to be found at the junk yards here and I don't really want to spend 1k on new heads. Also, can I reuse the stock springs with this cam if they are to spec? Any other thoughts or suggestions to help give this van some giddy up would be very much appreciated.

 

The lower intake is the biggest bottleneck on this motor(after the stock cam), once you take a close look at it you will see that the ports pinch down quite a bit as they get to the head gasket surface. I'm sure this was done to ensure enough surface area for a reliable gasket seal but there is room for improvement and certainly enough meat in the casting for some hogging.
The Stock E7TE heads are definitely restrictive on this displacement in the big picture but even without porting they flow well enough to make 275hp. So you don't need to do anything to them to see gains but on the other hand even if you never rev the motor high enough to make it's maximum HP it will still benefit from a better flowing head, more air sucked in with each stroke produces more torque. The bottleneck on these heads has always been the exhaust side, there is a thermactor bump in the roof that should go away and the port can be opened up some and the bowl area smoothed into the port
I'd also suggest removing the sharp edges in the combustion chamber and any noticable casting flaws but don't polish, a rough finish actually flows better than a glossy smooth finish.

The stock EFI system in these trucks have 2 limitations, the fuel system(pump and injectors) can only supply about 275-300hp and the speed density control system requires a smooth and strong vacuum signal to operate correctly, so you can't make too much extra power and lumpy cams that produce noticable idles are incompatible. That Crane cam fits within these limitations very well, it's ramps are mild enough to produce good vacuum but total duration is quite a bit more than stock so it does a much better job of filling the cylinders.

Stock valve springs will work with this cam but these things weaken with age so at the very least you should have a new set.

 

Thank you very much Paul. That is exactly what I was hoping to hear. Keeping the stock EFI is important and, with that in mind, have cleaned up some excess casting material like stamping and seams. Heads are done, intake is next. Regardless of the outcome, I will post the end results. There seems to be lots of videos on porting this head and intake but I don't think I've seen one where keeping the ECU was a priority. That should probably be my first clue. Thanks again for the info. Andrew

 

Does anyone know if I can run the Crane 444232 cam with GT40P heads on the 89 E150 351 EFI system? I may have a damaged head and the GT40 heads are considerably more expensive. I already have the cam as well? Is there a better head to use? Any help much appreciated.