Actually, a flame thrower is simple to build with a HEI ignition. Add a standard coil with spark plug & bung at the end of the exhaust pipe. Simply splice in a toggle switch(ON-OFF-ON) with each 'ON' feeding each coil. You will then 'toggle' between ignition and 'flame'..... by that I mean to build sufficient engine RPM's, then 'toggle' to flame, step on the gas(I run a 4 bbl), and voila, FLAME. I built this into my Koenig 2 yrs ago because I was tired of pickup trucks being a foot rearward of me, trying to see/climb into the engine bay..... makes for a good surprise!!!
Get rid of your cat, as the cat will try to absorb any unburnt fuel ! If you want a real long flame, add propane!!!....warning... the rear of a Fiero can get very hot.... carrying propane is like carry a bomb! I have never liked taking the BBQ bottle over to get filled!
Sandy