# Speaking of headers-head bolt hole question



## russosborne (Dec 6, 2010)

All the headers I have come across, from cheap to very expensive, say that there is a hole on the Pontiac head that may need to be tapped (or is it drilled and tapped? can't remember) to use them. 

Is there anyway of telling without taking the current exhaust off if the heads I have on the car have this done? Is it a certain year type thing, or just random?

70 Lemans with a 350 and Th350 trans and single exhaust is what I have.

If I have to remove the heads to have the hole taken care of, I will just stick with the stock manifolds for now. 

Thanks,
Russ


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## BearGFR (Aug 25, 2008)

russosborne said:


> All the headers I have come across, from cheap to very expensive, say that there is a hole on the Pontiac head that may need to be tapped (or is it drilled and tapped? can't remember) to use them.
> 
> Is there anyway of telling without taking the current exhaust off if the heads I have on the car have this done? Is it a certain year type thing, or just random?
> 
> ...


Hey Russ, the easy way to tell is to look at what you've got now and count how many bolts are holding on your manifolds. If you've got 6, (2 on the front port, 2 on the rear port, and 2 covering the middle 2 ports) you're good to go. If you've only got 5, then you know your heads will "need" the additional bolt hole drilled and tapped.

Bear


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## russosborne (Dec 6, 2010)

Cool, Thanks!
Russ


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## Mr. P-Body (Jan 20, 2011)

Russ,

To clear things up a bit...

'72-'74, for some inexplicable reason, Pontiac deleted the outboard exhaust bolts. I suppose a "cost cutting" measure. SOME of the heads still had the "boss" for the bolt, while others didn't even have THAT. It doesn't apply to the '70 castings, as all 6 holes ARE drilled and tapped in them.

Jim


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## russosborne (Dec 6, 2010)

Thanks. 
That might explain what I seemed to find last night. On the passenger side (haven't even tried the driver side yet) I could only feel 4 bolt heads. one on the first and last port, and then the two on the middle ports. Now, there is a lot of rust on the bolts that are there, and maybe the other two got broken off. I really don't know. 

Right now I am not sure just what engine I have. It isn't looking like the original since I think the vin is different(if I am even reading that right). Getting conflicting ideas about where the vin is supposed to be on this thing. I have the number just below the pass. side head, above the YU, but I can't tell if there is another number down by the timing cover. I am going to have to try to read the date code to see if it is even close to the right year. I might have to remove the timing cover to try to get a better look. 

Unfortunately I have to know what the vin on the engine is, due to Ohio regulations. I have a salvage title, which in Ohio isn't legal for street use. To get that issue fixed, I have to have the state inspect the car. They inspect all the vins and if they don't all match I have to have receipts for the odd ones, or I could go to jail if any are from a stolen vehicle, and of course this is how I bought this car. Will have to get a different engine if the vin isn't right. 
Russ


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## BearGFR (Aug 25, 2008)

russosborne said:


> Thanks.
> That might explain what I seemed to find last night. On the passenger side (haven't even tried the driver side yet) I could only feel 4 bolt heads. one on the first and last port, and then the two on the middle ports. Now, there is a lot of rust on the bolts that are there, and maybe the other two got broken off. I really don't know.
> 
> Right now I am not sure just what engine I have. It isn't looking like the original since I think the vin is different(if I am even reading that right). Getting conflicting ideas about where the vin is supposed to be on this thing. I have the number just below the pass. side head, above the YU, but I can't tell if there is another number down by the timing cover. I am going to have to try to read the date code to see if it is even close to the right year. I might have to remove the timing cover to try to get a better look.
> ...


Hey Russ, that string of digits above the "YU" is NOT the vin, it's some sort of sequencing number or something that was used during assembly, but I've not run across what it means. The vin, if there's one on the motor, will be down low on the front on the passenger side, just to the left of the timing cover. Pontiac didn't start putting the vin stamp on blocks until late in the 1967 model year though, so if your block is older than that - it's not going to have a vin on it anywhere.

So.... A good place to start would be with the 4 character date code, on the top rear drivers side of the block right next to the distributor. The first character will be alphabetic, and will be folowed by 3 digits. 


Date code letter deciphering:

The date code is 4 digits. The first digit is the month, the next 2 digits are the day of the month, and the last digit is the year (6 could be 1966 or 1976).

A=January

B=February

C=March

D=April

E=May

F=June

G=July

H=August

I=September

J=October ( also September for 1967 model year)

K=November

L=December

M=December (1966 Only, for 1967 model year)


Another place you should find the vin is on the TOP side of the frame rail (between the frame and the body) somewhere between the rear corner of the frame and the next body mount towards the front, on the drivers side. It can be tough to see because of where it is, sometimes a small mirror helps.

Bear


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## russosborne (Dec 6, 2010)

Thanks. 
I may have to take the hood off to get back by the distributor. I have gotten bigger and a lot less flexible over the years. 
Might be easier (for me) to pull the timing cover off. But that is going in the wrong direction. Want to get this on the road, not into a million pieces. 
Need to get a drop light first and see if I can see anything there before doing that though. Not too sure I can handle the hood by myself any more either. 
Getting old really bites sometimes. 
Russ


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