Flame throwers have been covered several times here. Do a search and you will find all you need to know to fabricate and install them.
I bought a kit from flamekits.com, may be spelled different. I have it on my 65 belair old school lowrider, with strait six and y'd dual exhaust, always works with no problem. The car must be warmed up though or it just dies out, keeps tailgaters away!
i've got a wiring diagram that will show you how to build your own controll box. all you'll need to figure out is how to get extra fuel into your exhaust.
the way i always heard it being done is to first get 2 model a coils,mount 1 spark plug in each exhaust tip, wire one model a coil to each plug, get a 2 way switch. wire the switch so that in the normal position you have power to your coil. when you flip the switch it will send power to model a coils and ignite the plugs in your tips. since you have no spark for this breif time to the engines plugs you engine will act like a pump, send raw fuel thru exhaust to be ignited by the plugs in your tips that now have power.
its not good to use your engine as a giant fuel pump, you'll wash the oil off your cylinder walls . one of my friends used NOS injectors and high volume fuel pumps to get fuel into his exhaust
I know the potential problems choking your motor will cause. What do the fuel injector flames look like? propane? What's best?
"Officer that's not a flame thrower. It's an emissions control device. You see I'm reducing the amount of unburnt hydrocarbons I introduce to the atmosphere."