I run one of these in my 1970 Coronet, 383 with automatic. I have been very impressed with it, no issues. Not sure off-hand which springs I'm using. I'll have to take a look when I get home tonight.
I looked into these, they offer a replacement style distributor as well and I just bought a Chrome Ignition box so I will likely go with that. $165 beats $416!
Well that sucks!
I went with the 4secondsflat as well. These guys really have their act together and very reasonable for what you get. Anybody looking for ignition should check these guys out before you buy.
I have an all mechanical advance on my unit from MSD with no vacuum at all. On mine the light blue and light silver springs bring the timing all in by 2500, the unit comes from the factory with the blue 21 degree advance stop bushing. The curve can be changed with springs of course and the amount of advance off of initial is determined by the bushing. Hope this is informative. And by the way, MSD is the balls....every one I know uses them and they are outstanding ignitions systems.
The problems I had were hard part issues. One was a 8546 BB distributor. The end of the shaft was not machined properly. Regardless of the oil pump drive shaft tested (all OEM Mopar), the tip would jam into the grove and it was hard to separate them even if joined by hand outside of the engine. Easy fix but it should have been right from the factory. The other was a 8534 small block. That particular model is not completely aluminum. The cap base is a black plastic composite of some sort. The cap would not set flush on the base. It rocked and you could see the gap at the base. We tried a new spare cap and the results were the same. Took it back back and checked the new one before leaving the store. It was the same so I just got a refund. Put the raggedy 15+ year old 8534 back in. It was obvious by looking that the plastic bases were different materials.
