Starfury

I have the MSD Ready-to-Run in my 331. It works great and is a hell of a lot easier to adjust the advance curve on it than on the factory unit. That said, it's not terribly cost-effective if you have a working factory unit, or can get your hands on a Duraspark for cheap. It is, however, rather handy if you want to add an MSD box, because the box plugs straight into the MSD distributor plug.

kenash

Hi,
I have what I consider a healthy prepared 331 (392 RWHP). I run a detailed curved factory distributor with a Pertronix sparkie and Jacobson CDI box. I'v run the MSDs, but found they were no better than what I run now. Thus, I sold them. There are a couple of folks who still have the skills and machines to perform a custom build and re-curve. It doesn't cost a bunch either. PM for a guy I used, if interested.

racer_dave

Setting the curve on the distributor would be for mechanical advance units. A Sun machine is needed, any good engine shop should have one. Or find a local racer, they should be able to tell you which shop to use. Setting the curve is basically changing the springs, weights and travel stops to fit the RPM range you want. But you need the machine to track your changes so you know if the changes are good. The shop let me stay the last time they did an HEI for my old street stock. We started with setting the travel stops, then we adjusted the springs and filed down the weights and kept tweaking both until it was where I needed it to fit my racing style. And yes, there was a noticeable power increase coming off the corner after it was done right.

I run an MSD now, but keep the old HEI for a backup. If the MSD goes out at the track I can drop the HEI back in and be running again in 10 minutes.