The distributor is model 8360 w/ external MSD SS coil.
I Read the instructions and i'm still a little confused.

It said it comes from MSD with the "heavy" springs installed, and gives different spring combo's for increasing the timing curve.

What does all that mean??? :confused:

By looking at their charts it seems you would reach max RPM quicker by using lighter springs.So why wouldn't you just use that set up?

I'm a liitle niave' at setting up a distibutor and always just dropped in a good used GM HEI.

Sorry for the DUMB question.

Anyhow I have a 69 396 w/stock pistons, 049 heads, Holley 750 single pump,and crane hydraulic cam . I have the cam card in front of me and it has 2 druation numbers. The first is Advertised @ 286/296 . @nd is duration 226/236. If that helps.

I don't race the car but would LOVE to get a quicker throttle response.
Any info on the best route to go to set up this distributor would be GREAT.


Thanks in advance.

@nd is duration 226/236


That should have read 2nd duration on the card says 226/236

You will have to try different spring combos and road test each time charting the effects they made. The other option is to take the distributor to a speed shop and have it put on a distributor machine and tell them what RPM you want the advance to come on at.

Thanks, hoping to get it close before I drop it in.

Also it is a 8361 not 8360 as I had posted earlier.

One other thing,
What is the advance stop bushing? Sounds self explanatory but i'm not sure what would be right for my set up.
They offer like 4 different sizes that stop advance from 18 up to 28 degree's????

Again dumb questions to most but I'm clueless on this....Sorry bout that...

You want it "all in" by about 3000 RPM. All in means you want your timing to be fully advanced by 3000 RPM. That is what most people do, but it depends on the individual. I would try the lightest spring setup for the quickest advance and pull out the timing light to see where it stops advancing (if you have a timing tape on your balancer). Otherwise, trial and error like the other's said. The stop bushings basically "stop" the mechanical advance at a certain point so it doesn't keep on advancing, causing detonation. The lighter springs don't make the engine reach higher RPM faster, just makes the timing advance faster. I guess it would be a cause and effect thing.

Start with medium weight springs, 14 deg base timing, plus 20 mechanical. ( so you would use the 20 deg bushing ) Whatever you get with the vacuum advance is irrelevant, unless you get into part throttle rattle.

Start the engine, set your timing, idle mixture, and idle speed. Hook up your timing light, have a buddy bring the throttle up to 3000. Your mechanical should be finished advancing by then. ( 14 + 20 = 34 ) If it isn't put a lighter spring on one side only. Retest.

Do some research on how to read plugs for signs of detonation. Take the car out and hammer it. Examine the plugs.

I am currently running 16* initial,20 in the distributor,all in by 2000. I had it the same way but all in by 2700 and didnt pick up anything. I have a Mallory Unilite dist w/no vacuum advance. If your ignition was in good shape before,don't look for any performance gain,unless the quicker advance does it.

what color is the 20 degree bushing?

http://www.msdignition.com/dist_mechadv.htm