I have a 91 lx with every upgrade out there: e303,gt40 upper and lower, bbk 70mm throttle body and spacer, , bbk cold air, edelbrock performer heads, frpp 1.6 rollers, shorty headers,  bbk under-drive pulleys, richmond 373 gears, pro 50 shifter, bbk off-road h, flowmasters.  With all of these upgrades, I still don't think I'm getting the most out of this car.  I think that it's the right combination but it surely does not run like it.  The idol is rough because of the cam but at times it acts like it wants to shut-off when sitting at lights etc..  I'm thinking that I may need to add: 24lb injectors, 75mm mass air meter, and possibly a new more powerful altenator.  Any suggestions?

Good luck on getting the most out of your car with the mods.I had a similar idling problem just this week. I noticed the idling a being rough a few times & thought it was time for a tune up.Also noticed low reading on my battry amp gauge.I thought I needed a new alternator with more amps.Took it to the mechanic on Monday & he adjusted the throttle body & it is running well.Not long after I purchased my car, I got a heavy duty battery since the car is loaded with electrical options such as power windows,vert top,power seats, high output stereo ....also replaced the started this past winter.Hopefully I's set for a while.

Hey this is conk, I forgot my password so I had to get a new one.

Thanks for the input on my LX. I changed back to the off-road  h, I think the air flow was being restricted on the way out.  Also got a tune up, one of my plugs were shot, I found out that the idiots who did the work on it used the same plugs that were in the car when I took it into the shop. Aside from that, the workmanship was horrible.  I tried to save money and got burned.  Anyway, I actually took it to the local ford dealer to get it done right and it runs like a demon.

Keep on Pushin!!

Good to know that you are back on the road bro & running well.It was good to know that you didn't have a big repair bill, just something simple.Keep rolling & enjoy your Stang !

i think the problem may be that the car needs a computer tune, i had similar problems myself. it is a must