Another breather hose question

On my '90 PCM, I have a breather hose coming off the starboard valve cover, which connects to the flame arrestor. The port valve cover has a PCV valve, which is plumbed to carb spacer.



To make sure my roller rockers will clear (and because they look cool), Ill be installing new valve covers this spring.



On the new valve covers, the cut outs for the oil fill/breather hose are on the opposite side compared to the stock PCM covers. Does it make a difference which side the breather is on vs. the PCV? Ive seen it set up both ways, so I imagine it doesnt matter, but it doesnt hurt to ask.

I could always turn the spacer around so the PCV port is on the front, which would allow me to keep the PCV on the port side without running longer hoses. If it makes no difference, Id like to put the PCV on the starboard and not remove the carb.

I should now be able to close the motor box AND keep the 1" spacer with the new low profile flame arrestor* I just picked up.



*You wouldnt imagine the trouble I went through to find this flame arrestor! Thank you to everyone who I asked/harra$$ed to swap with me, and to those who helped me with my search!

It does not make any difference which side the breather and pcv valve are on.

TRBenj wrote: The RR's may have fit under the stock PCM's, but they will definitely fit under these, hence the switch.

Not to mention they're an awesome looking cover

boat dr wrote: TRB;at one of the schools i went to,either Yamaha or Mercruiser,one of the students asked a question. The "teacher" answered with a very good point.With that answer many times i have relived that day in the cla$$room.His reply was "DOES THE MOTOR KNOW".There are lots of "things a motor knows,Spark,Fuel,Timing and a host of other variables. but it don't know or care where that hose is connected........ boat dr

Thanks for confirming my suspicion Doc. I couldnt think of a reason it would matter, but Im far from an expert. I had seen it set up both ways, but it seemed that RH PCM's have the PCV valve on the starboard, the LH on the port. Just a strange coincidence, I guess.

I put roller rockers on my Mustang about 8 years ago. You'll probably notice a big difference in the mid range power. I had to go with taller covers too. The bottom side toward the exhaust is tricky to screw down.

'doc, come on. That was probably the nicest post '79 ever had, he definitely could have layed into TRB but didn't. I think he deserves a little credit.

Very amusing.