# '67 GTO engine id



## swannee (Feb 26, 2014)

Good day to all, I am working on a 1967 GTO in the shop and I think I have a transplant engine in this car. I have a couple of questions also but first things first. I have tried to search for the engine id on the powerplant in this car and can't seem to come up with exactly what I've got here. The engine code stamped on the front of the block is 070312 YD. Near as I can tell this is a 400 auto block but I see no corresponding numbers on any list for the numbers shown. This is a 4-speed car. It also has an early HEI ignition which also leads me to think this is a transplant engine. I'm not that concerned that it is not the correct motor but I'm trying to replace the exhaust manifolds as they have had studs broken off in the past. The studs used for attaching the pipes have been welded in and are now broken off again so I would like to replace the manifolds. The numbers on the manifolds are: 9777646-1LHB and 9777642-1RHA. From what I've researched these are "D" port heads used on HO and RA engines. Am I correct in assuming I can I replace these with new stock manifolds from the various vendors out there? Also I want to replace the harmonic balancer assembly which I have found. I also want to replace the crank pulley but I do not see any repro. pulleys for this engine. It is a 2 belt pulley #9786713. Does anyone know where to find a pulley? Thank you for any info.


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## BearGFR (Aug 25, 2008)

Web search "Pontiac engine codes" and you'll find a plethora of sites that tell you how to ID what you've got (including here).

Start with the date code first to nail down the model year, then you'll know what that YD really means. Cross-check against the block casting number. The number you listed with the YD is just the engine build sequence number. You won't find any reference to that except (sometimes) in the car's original build documents, available for a fee from PHS.

Yes, pretty much all D-port heads and manifolds are interchangeable. Depending on year, there were some heads that "left out" the end bolt holes which made them difficult to fit with headers. Pulleys, it's important to get that one right because they varied a lot - even in the same model year. My favorite source for good quality pulleys is Ram Air Restorations.

Bear


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## swannee (Feb 26, 2014)

Thank you for your response Bear, what I found on the rear deck under the dist. is a J166 and a set of numbers 86133 but I think there should be a 97 ahead of that number but it appears the factory machined a hole and plugged it ( oil pressure?) taking off the first 2 numbers. Is that possible? With the 9786133 number I could then find on the id list that this indeed a '67 400. I still feel this motor has been put in the car replacing the original engine somewhere along it's life. Am I right in assuming this? From what I've learned on the engine ID site the YD code is a block built for an automatic equipped car. Again I'm not too concerned about that just want to make sure I know what I have before ordering parts.


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## BearGFR (Aug 25, 2008)

J166 date code: October 16,1966 - which means it's a block that was cast for model year 1967. (The engine foundry 'changed over' to the next model year at mid-year). 1967 YD would be a 400, originally fitted with a single 2bbl carb, wearing casting number 143 heads, and installed in a B body (big car) with an automatic transmission. 9786133 (passenger side rear of the block, below the deck, next to the transmission flange) also indicates a '67 400. What heads are on it now? They too will have a date code in the same format as the block, and a casting number - usually on top of the center exhaust ports.

Bear


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## swannee (Feb 26, 2014)

Morning Bear,
The heads have the 670 casting code


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## BearGFR (Aug 25, 2008)

Those are definitely 67 GTO heads. 2.11 intakes, 1.94 exhausts, screw-in studs. They flow pretty well. The only negatives are that they're closed chamber and therefore need more timing than open chamber heads. That was ok in 67 when we had high octane leaded fuel --- not so good today. I assume it's a 4bbl? If whoever put it together also used the 67 GTO cam, then you have for all practical purposes a stock 67 GTO engine.

Bear


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## swannee (Feb 26, 2014)

Thank you very much Bear, I really appreciate all of your knowledge. The car does have a 4bbl but as far as the cam... who knows. The owner has had the car for 30 yrs. and has not been into the engine so whoever worked this over did it before that. So I guess I'll work with what I know and we'll get 'er back together. One more question if you don't mind, the cooling fan looks as though it's not right either. Is there supposed to be an aluminum spacer between the water pump and fan? This is a non-ac car so I don't believe there should be a fan clutch or spacer, I think the fan should be a 6 blade fan ( 5 blade now) bolted directly to the water pump. I was looking at an online parts catalog and they don't even show a spacer for this application. After some thought I went and looked at some images for 400's and I do see a spacer between the fan and the pulley, so now I don't know where to find one if I need it as the catalog I looked at does not show one.


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## ALKYGTO (Mar 29, 2010)

Optimally you want the fan blades 1/2 way in the shroud. Correct or not you don't want your car to run hot. Unless you are concourse showing it I would try to stick to the correct fan placement for optimal cooling.


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## chuckha62 (Apr 5, 2010)

Hmmmm... My '67 (non-A/C car) has a seven blade aluminum fan with the factory fan clutch. Ordinarily the clutch is a good thing.


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