The Stovebolt Site Forums The Shop Area Engine Shop Tony, or others who have HEI dizzy on a 235

I tried emailing Tony, but the message bounced back, so I'm pestering anyone who has converted an HEI dizzy. I got one from the "recycling facility"(can't call them junkyards anymore) out of an '80 250 I 6. Tony put up a picture of his holddown clamp and said to trim off the collar so it will fit further down in the block, and something about grinding 3/8" off the bottom of the shaft. Do I need to change the driven gear? Is there a website with instructions and/or pictures? The dizzy I got has a short shaft extension held on with a roll pin which is slotted on the end to engage the oil pump, did I get the wrong dizzy? Do I take this off, or leave it on? Please help, so far I have a whole $35 invested and don't want to screw it up. I plan on having the coil checked, and replace the cap and rotor. Should I replace anything else? I checked the vacuum diaphram and it works okay. I'm dosing up the centrifugal advance with PB Blaster, because rust from sitting had made it seize up. Should I plan on replacing the weights and springs?

Bones, you don't need to touch the drive gear or its location. Many of those HEI's have that u-joint, its no problem.Carefully measure from the tip the the dist shaft to the bottom of the teeth on the drive gear on both distributers.The HEI is about 3/8 inch longer.Shorten the shaft with a grinder or file(slow), then reprofile the end to look like the old distributer. Check your work ,making sure the length and tip are correct.Hack saw off the collar and dress it with a course file.It does not have to be finely machined, the factory machined bottom section locates it.Make a clamp or you can butcher up the origial to work( better to save the original) When you install the dist, its very important to have it fully seated into the oil pump.Cleaning up the advance should work ok.If you have a fancy timing light with total advance features ,set the total advance at 32-34 degrees with the vacuum advance disconnected, but setting the timing with a vacuum guage or on the stock 5 degree setting at idle will be fine on a stock engine.Have fun

Tony, thanks for the speedy reply. I don't have a fancy timing light, but tell me more about timing it using a vacuum gauge- that I have. The engine is .40 over with a Corvette cast iron dual exhaust manifold with heat riser and has two Holley Weber progressives on a two carb Offenhauser intake manifold. Currently the cam is a stocker with hydraulic lifters. TIA.

Bones, you set the timing at idle for the highest vacuum reading. I always set the timing for total advance with a light that has a degree meter.On some tuned engines setting the timing with a vacuum guage may result in less total advance at higher speeds, at least in my case it did.I'm not the last word on this, perhaps some else will reply with their experience.