If I have vacuum for the brake booster and fuel pressure regulator, can I just block off the other vacuum lines? I am not going to run an EGR or any emissions stuff.
Picture A is where I get my brake booster and FPR vacuum, and the drivers side picture has one of the lines I need to cut and plug.

 

I had to plug a few on mine, so you should be good.

 

That set-up will never fit under a stock hood of a Miata. My advice would be to ditch the fancy valve covers and upper intake spacer unless you are planning to run a huge hood scoop, and I know about huge hood scoops.

 

I have a feeling that you are going to have to get creative when trying to attach the heater hoses at the firewall because of those valve covers.

 

To answer your question, yes, you can cap off the unused vacuum ports. As far as the one that you have circled (and the other one supplying the PCV) I would cut those off/ remove them and install threaded plugs and pick up my PCV vacuum elsewhere.

 

I have Ford Racing covers and explorer intake. I had my lower machined down per Martins suggestion and also have my subframe shimmed down 1/8. I had to use EGR spacers to move my TB out to clear the valve covers. Still have not tried closing hood, that is coming up on the to do list. I had to plug the ports on the intake as well.

 

I'm not worried about the hood, you can check my build thread the car is not a sleeper. The valve covers were necessary to clear the rocker arms on the AFR heads.

 

Ford Racing roller rockers will fit under a stock valve cover from a 1987-1993 Mustang.

 

Hi,

TBone is correct. This wont fit and I have just been through it myself to know

Yes you can simply remove those fittings and plug up the intake with a screw in bung for the front port and a good silicone sealer for the rear fitting.

There are other rocker covers that you can use (as suggested by TBone) but there is also a great cast alloy type from trickflow for the ford 5.0l, which are lower profile than the ford racing set you have now (which look to be the tall version) AND they clear a studded rocker setup. I am using these now in my build.
No spacer is required between the upper and lower intakes to get this to work.

You will still likely have clearance challenges but the removal of the spacer gets you 3/8-1/2 in closer to where you need to be.

Also TPS switch may be the biggest headache from a clearance perspective. Well it was for me








The heater hose and Air cone line clearance

 

To add, I have the shorter finned FR valve covers, not the tall ones in your pics.