# Timing marks



## johnhalg (Oct 2, 2021)

Just pickup a 67 gto with a 400 looking at crank damper I have two lines on water pump housing have three 4,0 and 6 what do I use to time this engine also not a gto 400 10.1 but a 400 8.6 compression


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## PontiacJim (Dec 29, 2012)

johnhalg said:


> Just pickup a 67 gto with a 400 looking at crank damper I have two lines on water pump housing have three 4,0 and 6 what do I use to time this engine also not a gto 400 10.1 but a 400 8.6 compression


Assume it is a low compression 1967 400CI? The timing cover will have the 8-bolt water pump if it is 1967.

You will have the three timing marks as you see, 6 - 0 - 4. 6 degrees Before Top Dead Center (BTDC), 0 degrees, and 4 degrees After Top Dead Center (ATDC).

You want the timing mark on the balancer to line up with the 6 degrees BTDC. That is factory. However, the engine may run better at 9-12 BTDC. It is something you can play with to see if it starts/runs better. If it starts hard, then timing is typically too far advanced and needs to be retarded. If the engine "pings" under load, then the timing needs to be retarded a little until it no longer "pings."

Timing and timing curves have been covered quite a lot. Do a search using the search box up top of the page and you will find more info on timing.

Look at these Tune-Up Specs and they should help. Click on the pictures to enlarge them.









Pontiac Tune-Up Specs 1955-70


Purchased a 1970 Tune-up Guide for both cars and trucks. Neat little handy booklet. Here are the specs related to Pontiac which spans the 1955-1970 models. Just click on each of the 5 documents to see any of them, then you can expand those for easier viewing.




www.gtoforum.com


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## johnhalg (Oct 2, 2021)

Jim, TKY, I have two lines timing Mark's on my balance about half inch apart which line do I use


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## PontiacJim (Dec 29, 2012)

johnhalg said:


> Jim, TKY, I have two lines timing Mark's on my balance about half inch apart which line do I use


Look at the tune-up specs. The only balancer with 2 lines appears to be the '65 and earlier balancer. So use the first line based on that diagram.


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## johnhalg (Oct 2, 2021)

Jim Tky, I did and set at 9 bftc, had a water hose leak so did not try waiting for hose, tomorrow. Jim I appreciate all your time and patience. I had a 64 gto convertable with trips but that was 50 years ago , wanted to give to my son but was not interested so 35 yrs ago sold it cheap. I picked this up recently forgot lot of info. I am starting to ??? My self.
On this 67 GTO I have a block # 218401ya which is not a GTO engine and the heads D299 manufacture date I think, with 47 code in the center which may be for a 350 which really is confusing me. Also I go to replace the points and I find a PETRONIC 3 MODULE WHAT IS THAT I have no idea. I know it has some sort of cam by the looping. The person I purchased really knew nothing about he purchased and sort of gave up. Any info that you could help provide I would greatly appreciate I am 74 year old Veitnam vet. Again thank you for you help and more so your patience, JOHN


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