We have a tbird we've been racing for several races now. it was perfectly reliable until we started getting greedy and messed with the engine.
Some thoughts:
1) Weight is your biggest enemy with this car. I went through and stripped everything I could (down to unused wires in the harness). With the V6, it was 3000LB with full fluids and no driver. With the 5.0, we are now at 3150LBs. I wish we could get to 2750LBs but even if we got stupidly cheaty and bought a tube frame front kmember, aluminum rear LCAs and diff housing from a Mark VIII, and an all aluminum 302 block & heads from a race shop, I don't think that's possible. There's simply too much car. OTOH, It's relatively safe given the vehicle's bulk (I have no idea how anyone straps themselves into a Mini Moke voluntarily).
2) It sounds like you have an 4r70w auto trans.
a) Read up on the JMOD -- the idea is that opens up some holes in the transmission valve body to lower the amount of heat transferred to the fluid at the expense of shift harshness. While you are in there, there are a few common wear items to replace (Pressure regulator valve, PRV solenoid) as well.
http://tccoa.com/articles/tranny/index.html
b) Install a bigass trans cooler. This can be done for free using your AC condensor. Ignore the naysayers who say that there will be too much of a pressure drop (we didn't see it).
c) Avoid WOT shifts from 3-4 as this will kill your trans. The simple solution for us before we swapped in a manual was to turn OD off.
http://forums.tccoa.com/showthread.php?t=79692
3) The tbird 8.8 IRS is different from the diff found in the Mustangs BUT you can use the 8.8" Pinion & ring gears from a solid rear axle diff.
- If you can find one, you might wanna keep your existing one as a backup and then rebuild a second one with shorter gearing as your "race" diff. This diff is popular with the V8 Miata and IRS Cobra kitcar folks so you may find it easier to get a whole parts car to get these bits.
- We have 3.73:1 gears which make 1st gear kinda useless (very short) but it definitely woke the car up. I picked up these gears for cheap used ($30-60) and spent a few more bucks on the bearings/etc to rebuild the IRS.
- NOTE: the tractionLOK unit must come from an 8.8 IRS diff (most commonly found with tbird SC but was also an option on some cars. A rebuildable unit typically costs ~$75/used.
- Some folks who race MN12s have cooked their diff oil but this hasn't happened to us yet. If that happens, you may need to look at ways of cooling the diff.
4) We cut up 4 donor cars to get spare parts for our tbird. I did this before I had a son though (plenty of time) and was smart enough to tow the cars to a friends house so my wife never saw these carcasses.
- Early SCs can give you a spare rear diff/axles, thicker sway bars, stiffer springs, a manual pedal assembly, skinner brake pedal (or cut your own down and sell it), and the hydraulic clutch master cyl plus ~$1200-1500 in parts to resell (based on my experience)
- We have a 5.0 v8 so we could use the SC's M5R2 transmission (3.8/3.8SC/5.0 all use the same SBF bellhousing pattern). Since your bellhousing pattern is different, you will need a T5 from a Mustang, hydraulic clutch conversion, and you will need to fabricate a shift linkage to place the shifter a few inches rearward.
5) Don't forget better brakes. 99-04 Mustang GT calipers bolt right up.
http://www.tccoa.com/forums/showthread.php?t=57171
Myopic Motorsport's #888 Ceci n'est pas une Citron Thunderbird ("This is not a lemon" but a 1995 tbird w/ 93 V8 swap + shopping cart rear wing + engine mounted frito maker)
2017 Sears Pointless Organizer’s Choice
Frito Making Tbird from 2018 Sears Pointless Engine Heat BBQ -
http://goo.gl/csaet4