Thread: points to hei

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Barb, just few comment to add to what has been put out there. I'm not trying to sharpshoot anybody and hope nobody takes it that way, I've just been living these engines the last year and they are a bit of an odball with a few quirks.

As far as a an HEI distributor, the 75 and up 472, 500 AND 425 are a direct drop in and you can pick up a reman from rock auto for $115 plus shipping (makes the JY one sound a bit high to me). Which ever way you go make sure you get one with a vacuum advance as these are the ones that are NOT computer controled.

All the internal parts from the a Chevy HEI, distributor cap, rotor, coil, mechanical advance parts and module interchange with the Cadillac unit. The Cadillac HEI are not known to have an optimum advance curve so the distributor recurve kit with adjustable vacuum advance like Summit sells iis not a bad upgrade if you want to play with getting the optimum performance out of the Caddy engine......THAT BEING SAID THE CADDY HEI UNIT WILL DROP IN AND RUN PERFECTLY.... YOU CAN JUST GET A BIT MORE POWER OUT OF THE EGNINE BY FINE TUNING THE IGINITION.

UNLESS the timing tab or lower pulley has been changed there is no need to worry about verifying the timing mark which is a notch located on the innner most ring of the lower pulley. The big Cadillacs use a crank hub like an FE Ford with fits on the end of the crankshaft, the harmonic balancer is a seperate piece that sandwiches between the hub and pulley and then the pully is bolted to the hub. Basically it is impossible for the timing mark to slip on these engines.

Now having said that I did notice in one of the pictures you posted that it looks like you are not running a smog pump and unless your 472 is a 1970 (one year only) your belt setup should look like the first picture. If you are running with a 1970 belt set up which deletes the smog pump (picture 2) chances are that the lower pulley WAS changed. The timing tab would have had to be changed to match the new pulley for the timing marks to be correct.

The simplest way I’ve found to verify the timing marks is partially as Richard say, pull number 1 plug and put a finger over the plug hole while turning the crankshaft over with a large wrench. When you start to feel compression you know the piston is coming up on TDC and getting ready to fire. I normally use a long screwdriver at this point. Gently put it down number 1 sparkplug hole until it contacts the top of the piston and slowly continue to turn the engine over until it reaches the top of the stroke (you can feel when the screwdriver starts to drop meaning you have just past TDC. Check the timing marks at this point and they should line up. If they don’t remark the pulley with the new timing mark.

Thanks for the heads-up on the damper Mike.

thanks mike and tech. i will check the wiring. i am not running a smog pump as i removed it and all its piping. my engine looked exactly like the first picture when i got it. i also removed the ac pump. the wiring for my hei was done when i got it. i will have someone that knows wiring better than me to check the gauge of it. thanks again.