First off my El Camino has a late model 350 (dated 1975 by block number), with HEI distributor. I dont know if the HEI came with the engine from factory, or was added later....it was all in the car when I got it.

First, off I cannot reach the distributor clamp bolt to loosen or tighten it (damn you Chevy for the rear mounted distributor! :evil: ).....and I need to buy a proper distributor wrench, but do not know the size. It appears larger than a 1/2", so I am guessing its a 9/16"...does anyone know?

second, I dont have a factory book for this year model engine, so can anyone tell me what the timing should be set at, at least to start with?

for the vacuum advance, how much vacuum is required? I have a gauge but do not know how to know if the source I have (from the carb) is enough?

can someone tell me the easiest way to 'test' the coil, to see if its putting out what its supposed to?

Thanks in advance for the help.

Mike

1-should be 9/16"
2-start with 8 degrees BTDC and if you have no pinging go to 10 degrees
3-connect to timed vacumn source at carb (disconnect when setting the
initial timing)
4-if the coil is old replace it, they do wear out, otherwise there are
fairly inexpensive testers hat correlate spark lenght to voltage

My recent experience suggests that perhaps rather than trying to set initial timing it may be better to go for total timing. Of course if you have a stock sub-optimal mechanical advance curve this may not work so well.

In my particular case I do not seem to be getting the advertised 20 degree advance from my HEI, even after installing a performance curve kit. So setting total actually gets me in the ballpark much better. Just means that I see close to 20 degrees initial. Does not, so far, diesel on shutoff nor have I heard it ping.

Of course the other complicating factor is my lumpy idle which leads to a fast idle. I guess I have just a bit of cam in my BB 8O

(or that I need to figure out how to tune it, which is probably very true as well... where is the CPU on this thing anyways :lol: )