I'm running the Escort/Focus cam setup with double valve springs, new retainers, and new seals. I coupled that with the FocusSport Diablo Delta chip and I hit a 7k rev limiter. It pulls all the way up to that and wants more. I also installed ZETEC injectors and wiring for a little extra fuel. In addition, I have the BDR adj. cam gear set at 4* retarded. Works well, even on my autotragic.
All my Focus friends used to give me crap about my SPI. With the things I have done, it easily keeps up with them. I just ordered the ARP stud kit yesterday for installing my ported and polished head. With that installed, it should really go. The head on the SPI is the constriction, not the exhaust or the intake. Port and polish would be the best money spent instead of CAI's and exhauste for first mods. I understand that not everyone can either afford or perform a port and polish, but it will give you the most bang for the buck.
As for future upgrades, an IHI turbo is very soon. I have an 88 T-Bird TC and I just got the T3 in yesterday. The IHI from that car will go on the Flocus. I only intend on pushing 7-10 PSI, but is will still be fun.
At some point I'll blow the tranny (eeewww, that sounds way too Eddie Murphy, doesn't it?). Then I'll go with the manual. The car will be paid for within a year, and I have others to drive if she goes before that. The stock tranny will only handle 135 ft/lb of torque. It's pretty weak, but I have a few tricks up my sleeve, too. I bought another stock tranny cooler off Ebay and installed it directly behind the upper grille. Then I looped the original and the second together so it gets the fluid double cooled. I am also running B&M Trick Shift, just for fun. I regularly pull the pan and look for junk, and change the fluid regularly. Level 10 makes a tranny kit, but it's 5k. Too rich for my blood. There was also a write up in MM&FF recently about a new company that makes kits for much less. I may also go that route. Changing the tranny means changing the ECU, and with that goes my chips. I have too much invested to just walk away. I'm keeping my options open. There's a guy on another site who is working to make the ZETEC manual fit the SPI. I'm keeping an eye on his work, too. If it works, I'll go with that.
My indicator module went out, and I had lost 1st gear. I thought the tranny was going out, but it finally threw a code when I removed the Diablo chip. 50+k miles and that's all that has happened. Pretty good so far, especially how I drive it.