I have one of the earlier Holly Pro-Jection systems mounted on a 261 in my (my wife's) 40 Chev convertible. It is the 2 barrel version and seems to be working quite well so far. Good mileage and excellent response. The current versions are a great deal more involved with Oxygen sensors and computer programming. I talked with a fellow at a recent car show who had a 261 powered coupe with the latest Holly setup and he was still working on the calibration. He was an engineer and from looking at the calibration curves, computer hookups, etc...it might help to have a degree in engineering! Could be a lot of fun however.
