I'll try to help. I have an On3 kit that will be going on my coupe soon.
1. Your green top 42lb injectors will work.
2. The car will need to be converted to MAF unless you plan to run a standalone ECU.
3. There are companies that do mail order tunes, but I would honestly take it to a reputable tuner in your area for a tune.
Instead of buying a new tank, figure out where yours is leaking from. It sounds like it could be from the fuel neck rubber grommet. As far as the fuel pump, it sounds like a standard Walbro 255lph will work for what you're wanting. They're only about $100. I would go ahead and pick up an adjustable fuel pressure regulator as well, that will help get your fuel pressure set correctly when the car gets tuned.
The turbo blanket isn't required, but it would be a very smart thing to buy. It will help keep the underhood temps down, prevent stuff under the hood from being melted, etc. It would be a good idea to get some header wrap and wrap the down pipe and crossover, do not wrap the headers.. I've read that this can promote rust.
Once you convert the car to MAF, pick up a VMP HPX 05+ slot style MAF, flange, and pigtail. Hopefully this helps a little.
Figured I would introduce myself and share some history on the car
I'm a part time car dealer and bought this car from a wholesaler. I originally wanted to sell it for profit but I had some stress in my life and it was the worst of my problems. I ended up driving it as a daily for 2 months. Anyways. The car is all original 1988 5.0 lx aod. Sometime in 2005 the trans was rebuilt. The original owners son made his father sell it because he was too old to drive. The car runs great and now that's I've decided to keep it, it needs alittle more go. I originally saw the cxracing kits on eBay and eventually found the on3 kit. My questions are
1. Is this the fuel pump I need?
Part No. 12-915
Avenger; Forced Induction Series; Performance In-Tank Electric Pump; 255 LPH
Electric Fuel Pump; In-Tank Electric Fuel Pump; 255 LPH; Forced Induction
HFP 255LPH Fuel Pump Ford Mustang GT 5.0/4.6 1986 - 1997
2. I have ford green top injectors from my pro charger ls1 build. Will these work?
3. Do I have to convert the car to maf?
4. Does it have to be dyno tuned or is an off the shelf tune available ?
5. Is the turbo blanket required?