# Flavors of 389?



## DukeB-120th (Oct 19, 2009)

So, I was talking cars with Dad last night... At risk of evincing a serious misunderstanding of this engine stuff, I have a question.

When my dad was daily-driving his 66 Goat back in the day, his timing chain broke apart and nasty metal fragments worked their way into the engine somewhere and fouled it up. It was costlier to have the engine fixed than to drop in a brand new shortblock, and it was his daily, so he went with the short block and had the old, original subassemblies put onto that new core.

He mentioned regretting this decision, as it obviously permanently ruined the matching numbers aspect of the car, but he also mentioned "not knowing if that new 389 was a GTO 389 or not."

The question is _Is there a GTO-specific type of 389 that went into cars like his, or is such a block generic? If there is a difference, would it be noticeable/significant?_:confused

One more thing, what the heck is an IA II?:confused


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## jetstang (Nov 5, 2008)

The date code wouldn't match the build date of the vehicle. Also, the engine 2 digit code probably didn't match the GTO. If the engine wasn't for a GTO it could have the big car cam in it. The compression also could be down, but beyond that, not much difference.


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## Eric Animal (Oct 28, 2007)

An IAII (IA2) is an aftermarket block made by ALL PONTIAC. It is very strong, has many improvements over a stock block (ie splayed 4 bolt mains, a reinforced lifter valley, etc) They are available in cast iron and aluminum. I have included some pics below.


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## BearGFR (Aug 25, 2008)

jetstang said:


> The date code wouldn't match the build date of the vehicle. Also, the engine 2 digit code probably didn't match the GTO. If the engine wasn't for a GTO it could have the big car cam in it. The compression also could be down, but beyond that, not much difference.


:agree If all they changed out was the short block, then depending on what was used it's likely that the only thing that changed was the cam. The block itself would have been generic. There was only one 389 block for model year 1966 and it was part/casting number 9778789. If whoever did the work happened to have reused the original cam or if the assembly was bought from GM specific for the GTO, then it would have been essentially the same motor. The only thing "lost" was the matching numbers/codes.

Bear


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## DukeB-120th (Oct 19, 2009)

BearGFR said:


> :agree If all they changed out was the short block, then depending on what was used it's likely that the only thing that changed was the cam. The block itself would have been generic. There was only one 389 block for model year 1966 and it was part/casting number 9778789. If whoever did the work happened to have reused the original cam or if the assembly was bought from GM specific for the GTO, then it would have been essentially the same motor. The only thing "lost" was the matching numbers/codes.
> 
> Bear


Okay! Thanks for the info guys. It confirms my original suspicion, but I was really starting to second guess myself there for a while.

And the IA II blocks, how many guys are running those?


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## jetstang (Nov 5, 2008)

DukeB-120th said:


> And the IA II blocks, how many guys are running those?


1, that guy from New York with too much time and money!! :cheers
Eric, can't wait to hear it run, that thing is a monster..

You could always stamp the right code into the front of the block if there isn't any codes there.. But, if you have the receipt showing that the motor was swapped out under warranty, then it's not the "wrong" motor for the car.


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## Rukee (Feb 8, 2007)

If he had documentation that the dealer installed the short block, it shouldn't hurt the value of the car.


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## geeteeohguy (Feb 2, 2008)

Duke, I'd be curious if your block is a "service replacement" block. What is the casting #, the 2-digit code, and the date code? That would shed some light on this. Also, if documented, this is all part of the car's "history", and not totally a "bad" thing. Stuff happened, things broke, things got repaired. You're very lucky that there was a GTO in your family. We had a Peugot and a Renault Dauphine.


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## 66tempestGT (Nov 28, 2009)

Eric Animal said:


> An IAII (IA2) is an aftermarket block made by ALL PONTIAC. It is very strong, has many improvements over a stock block (ie splayed 4 bolt mains, a reinforced lifter valley, etc) They are available in cast iron and aluminum. I have included some pics below.


i guess if your engine doesnt have a place for water you can save a lot of money on radiators and hoses and water pumps and silly stuff like that.


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## Instg8ter (Sep 28, 2010)

+1 for Rukee and GeeTee, a service replacement is part of the provenance of your car, especially if dealer installed, no different than a new water pump....etc., sure all the casting have been replaced on our cars a few times so there are many parts that are not "numbers matching".

found this:
"Service Replacement (SR) blocks do not always have a code stamped on the front of the engine. They do, however, usually have a casting number. This casting number is usually on the RH side of the rear portion of the block - where the transmission bolts up.
Here they are:"

Technical Information: Pontiac 400 428 455 Casting Numbers


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## jetstang (Nov 5, 2008)

geeteeohguy said:


> You're very lucky that there was a GTO in your family. We had a Peugot and a Renault Dauphine.


If your dad bought those cars you are lucky to have been born--GAY!! :cheers
My family had big Buicks and Olds.. Lucky we had long cold winters, I was convceived on new years eve, Happy new year!!


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## DukeB-120th (Oct 19, 2009)

Well fellas, ya'll want me to go look up numbers, but I can't do that because the car was sold in the late 90's. Also, I'm sure it wasn't under warranty or anything because the shortblock was installed in the late 70's or early to mid 80's.



jetstang said:


> If your dad bought those cars you are lucky to have been born--GAY!! :cheers


HAHAHAHA.



jetstang said:


> My family had big Buicks and Olds.. Lucky we had long cold winters, I was convceived on new years eve, Happy new year!!


Some things are better left a mystery.



> i guess if your engine doesnt have a place for water you can save a lot of money on radiators and hoses and water pumps and silly stuff like that.


Say What? eek:


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## 66tempestGT (Nov 28, 2009)

looking at the pics of that block i see holes for pistons and holes for bolts but no holes for water to run through.


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## geeteeohguy (Feb 2, 2008)

Yeah, Duke. It's amazing I'm not an interior decorator! My folks were stationed in Germany in the military and shipped those cars back stateside. Little French cars that worked ok on 10mph cobblestone streets in France, but self-destructed on the high speed interstates of America! Actually, after the Peugot got sold and the Renault blew up, we got a brand new '63 VW Bug ragtop and a '64 Ford Galaxie fastback that we had for another 30 years. In the '60's, I spent a lot of time across the street with the neighbors...they had a Jag XKE, a Corvair Corsa convertible, an MGB, and a Honda 305 superhawk...pretty cool stuff to a kid like me. We got a one year old '66 Mustang in '67, and that was super cool (except it wasn't a GT or a Fastback). I got into Pontiacs much later, in High school, when I learned to appreciate FAST cars.


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## BearGFR (Aug 25, 2008)

66tempestGT said:


> looking at the pics of that block i see holes for pistons and holes for bolts but no holes for water to run through.


Good eye. That's becaues IA-II blocks are shipped with no coolant passage holes in the decks. The intention is that the builder will drill whatever holes are need for the heads being used - not all are the same. It also preserves the ability to run the motor "dry deck" and plumb cooling to the heads externally instead of through the deck. This block is definitely an "engine builder's" block - it's not "plug and play" - the designers intentionally left some things either un-finished or semi-finished to allow more flexibility.

More into here.

Bear


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## geeteeohguy (Feb 2, 2008)

That's what I'm talking about: With Bear's knowledge (and thirst for it), and Eric's Bottomless Wallet, the rest of us in the Peanut Gallery stand to be treated to a whole lot of great info to keep us occupied until the burnout videos get posted!!!! Excellent!!


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## 66tempestGT (Nov 28, 2009)

BearGFR said:


> Good eye. That's becaues IA-II blocks are shipped with no coolant passage holes in the decks. The intention is that the builder will drill whatever holes are need for the heads being used - not all are the same. It also preserves the ability to run the motor "dry deck" and plumb cooling to the heads externally instead of through the deck. This block is definitely an "engine builder's" block - it's not "plug and play" - the designers intentionally left some things either un-finished or semi-finished to allow more flexibility.
> 
> More into here.
> 
> Bear


i was being a little sarcastic because he already explained this before. if i was going to run a "dry deck" i would still drill the holes and pour the block to minimize distortion. i am planning on doing this to my next dragster engine.


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## jetstang (Nov 5, 2008)

geeteeohguy said:


> That's what I'm talking about: With Bear's knowledge (and thirst for it), and Eric's Bottomless Wallet, the rest of us in the Peanut Gallery stand to be treated to a whole lot of great info to keep us occupied until the burnout videos get posted!!!! Excellent!!


I am with you!! Good stuff.


geeteeohguy said:


> It's amazing I'm not an interior decorator! My folks were stationed in Germany in the military and shipped those cars back stateside. .


Sorry, I wasn't calling your dad gay, well, I guess I did.. Just playing, but funny as hell.


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## geeteeohguy (Feb 2, 2008)

Hey, when I mentioned the French cars, I knew I was sticking my neck waaaaay out! I can't help it....sometimes I have to touch the cigar lighter to see if it's really THAT hot!! Hilarious stuff, IMO!!!!


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## 66tempestGT (Nov 28, 2009)

im sure his dad taught him plenty. but maybe not his pontiac but about fashion and things. oh and GUNS AND AMMO!


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