Tachometer Help?!!

[vrona@ix.netcom.com (Steven Verona)]

I want to add an RPM warning light to my 86 4kq autox race car.  I have 
learned that aftermarket tachs with lights and a tell tale are not made 
for the 5 cylinder motor.

The idea I had was to use 2 LEDs from radio shack and attach them to 
the tach.  One would light under a preset RPM (4000) and the other 
would light over another preset RPM (6500).  Any ideas on how to do 
this or if it is possible?  I would mount the LEDs inside my helmet and 
connect via a cord.  Kinda like my own HUD.  I think it will help me 
and, more importantly, psych-out the competition ;-)

Steven Verona