# Timming tab



## Nick 8999 (5 mo ago)

I have a 1975 400 block casting 557. It does not have a built in timming tab on the timming cover. I replaced the stock hub with a Proform 6.9 inch balancer. I did mark my cover rolling the motor to TDC in both directions and finding my center (0) however Im looking for a physical tab to install with the larger balancer. Does anyone know if this tab exists ?


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## BearGFR (Aug 25, 2008)

This isn't exactly what you asked (and I personally sometimes hate when people write answers to the questions I didn't ask) but...

A simple solution would be to make a mark on the timing cover that corresponds to TDC, then use a 'dial back' timing light whenever you need to check or set timing.
Like perhaps one of these

It's really hard anymore to find a product that doesn't have at least some bad reviews. Sadly, a lot of this equipment is made overseas and quality is suspect, so it can be a roll of the dice with regard to whether or not you get a good one.

The light I have is one like this and so far it's been good, but that doesn't guarantee that another one just like it won't be junk. I see the very same light sold under other names, Bosch for instance, at a higher price.

FYI I've seen it noted in "places" NOT to use a dial back light if you have an MSD ignition box or other system that fires the plugs multiple times at lower RPM. They "fool" the light.

Bear


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## Nick 8999 (5 mo ago)

Thanks for the reply BearGFR. I do have a dial back light and an MSD ProBillet Distributor/MSD6al box/MSD Coil. I'm looking for a Tab to confirm my marks are correct. Car runs 210 to 230 and I believe its in the tune. 
Nick


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## BearGFR (Aug 25, 2008)

Cool - in your case you might want to research this along with related issues "just in case" the MSD box is making your light lie to you, especially if the MSD is making it read "more" advance than is really there so that you don't actually have as much advance as the light is telling you that you do, so it's running a little retarded. That'll definitely make one run a little hotter. 

Bear


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## Nick 8999 (5 mo ago)

Good thread. I didnt know about the problem MSD ignitions created for timing lights.


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## Nick 8999 (5 mo ago)

Im still looking for a tab though if one exists.


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## BearGFR (Aug 25, 2008)

Nick 8999 said:


> Im still looking for a tab though if one exists.


Did I understand you correctly, that your balancer is a larger diameter than stock? If so, then the mark spacing on a tab for a 'standard' balancer will be off and will read "low" everywhere except TDC. You might consider using a timing tape on the balancer, one that has the right spacing for your balancer diameter, and instead making your own tab (possibly securing it under one of the timing cover bolts), that's just a TDC pointer.


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## Nick 8999 (5 mo ago)

I agree. The balancer is marked by the manufactor with 0 to 60* tape. I'm new to pontiac world. I have never had a problem locating a timming tab for any of my other GM builds. Typically you can locate a pointer or tab based on cubic in and balancer size. Just not for Pontiac V8 or at least that I can find. I guese I will build one and post pics of it in the future. 
Thanks again


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## BearGFR (Aug 25, 2008)

I did some looking, although the timing pointers are most frequently cast into the timing cover itself, apparently there used to be one. They looked like this. I haven't found a source for them yet though.

Bear


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## michaelfind (Dec 14, 2018)

BearGFR said:


> I did some looking, although the timing pointers are most frequently cast into the timing cover itself, apparently there used to be one. They looked like this. I haven't found a source for them yet though.
> 
> Bear


I believe I have one of those tabs but it will likely not work with an aftermarket balancer.


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## Nick 8999 (5 mo ago)

I have the same 1 that I used with the original hub however it will not work with the larger balancer.


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## PontiacJim (Dec 29, 2012)

Nick 8999 said:


> I have the same 1 that I used with the original hub however it will not work with the larger balancer.


You probably had the small solid hub like shown. 

I did find this and the year engine/car is listed, but not sure if it will really work or if you could adapt it? If the balancer has degrees, all you really need is a pointer or line that you can time off of. Easy enough to make that work with something like this.

ttps://www.rvautoparts.com/141-202-Proform-Parts-Timing-Tab-8-Inch-Diameter-
Balancer_p_380604.html


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