[goats2quick]

hey guys,
picked up a HEI dist, and want some feedback on weights.
it now has a aftermarket kit in it, and i want to replace with GM parts.
including module .

i have 2 sets,
396 center, 053 outers

346 center, 045 outers

wondering if one set is better than the other?.

motor its going in is a mostly stock 69 400.

i really dont know much on this subject, so any help would be great.

[25stevem]

I hope these give you some guidance.

[Joe's Garage]

Using 139 weights, he measured each combo.

Centerplate=======Weights=======Dist.Degrees
368=================139=============10======
406=================139=============12======
349=================139=============15+=====
371=================139==============9======
489=================139==============14=====
375=================139==============13+====
364=================139==============12=====
397=================139==============12=====
370=================139==============12=====
346=================139==============11=====
396=================139==============11.5===
398=================139==============10.25==
383=================139==============12=====

The use of 045 or 053 weights will knock exactly 1 dist degree from each of those numbers.

The complete thread is here:
https://forums.maxperformanceinc.com...s+center+plate

[25stevem]

If your learning and messin with stuff like this that can kill a good running motor real quick then you need to either get a timing tape to stick on your balancer, of carefully measure around it 2 1/8” and make a mark.

2 1/8” will be 36 degrees plus or minus 1 degree.

With todays average fuel and heads cast before 1971 you need to be real real careful running more then 36 degrees total, and this would of course be without the vacuum advance hooked up.

If your running the 670 heads they can depending on the cam used take more then 36 degrees, but they had better not have carbon build up.

Before you play around with timing on a old motor you should get a plant mister bottle and spray a a dam good amount into the carb while the engine is idling and then rev the motor up a good amount ,this will remove a large amount of carbon if the heads have that, if not then it will not hurt.

[Sun Tuned]

So looking at the chart there. Which is good because it’s been a long while since I messed with any 346 cams.

The 346 cam and either set of weights you have will allow 10 distributor degrees (20 crank degrees) or in the case of the 396 cam and either set of weights (21 crank degrees ), simply set your initial at 10 to start and you’ll be at either 30 total or 31.

Not a bad place to start at all.

Still need a bit more info on what else you have ,what’s been done/not done and some more info on what’s behind the flywheel/flexplate backwards….

But 30/31 total will sure get you started in the right direction.

Steve raises a damn good point…
Wonder how much carbon is in there????

Don’t go crazy trying to get that curve all in super fast…

[goats2quick]

thank you very much for the suggestions, and ill add more info on the car.

69 engine from a GP, it was gone thru maybe 18 years ago, stock crank and rods, .
crappy 8 relief pistons, Elgin cam, I think 443 lift.
points dizzy with a pertronix conversion and coil.
aftermarket balancer with timing marks.
heads are 62, with the basic rebuild.
350 trans, stock converter, 27ish rear end.
maybe 9000 miles on rebuild, but the car has sat for 7 years.

not running at the moment, as I've replaced the fuel tank, and sender, and now cleaning the carb.
should be ready to fire back up in a couple of days.

[25stevem]

Love those year GPs!

Those cars have a aircraft carrier of a hood!

You can’t remove one of those by yourself like I have done with a GTO!

Keep in mind that the HEI needs a full 12 volts from the run position of your ignition switch, not the normal 9 volts.