[PontiacJim]

The frame looks rough. Looks like someone has already cut out and replaced the right side (passenger) inner boxed rail. Very rough cut/weld and it was not fitted to the center body mount very well. Probably rotted away previously.

I would have your frame guy sandblast the frame and you take a look at it in its raw state before he does any repairs or paint. Sandblasting may blow some holes in any weak spots and you may want to see it before going any further.

You may want to also take a few diagonal measurements at this point to ensure the frame is not bent or sprung.

$600 does not sound crazy. But, if the builder finds any problems, the price will go up quickly.

 

[tonyskala]

Pontiac Jim- I was hoping you would chime in. So I thought the exact same thing on the repairs on the frame. But he had a frame from a 65 Chevelle and when we compare the two the both looked like that. I thought it looked like sloppy welding but he said it did not appear to have been repaired.

The frame is getting sand blasted on Monday. He has been good about letting me know on the repairs because he knows what I am after.

The real issue surface today when the bushings were being pressed out of the rear differential housing. One of the ears snapped. I was really upset about it. So I started about trying to find someone to weld it, and trying to find a replacement for it hoping one will pan out to be more cost effective. So I am now trying to find this differential for the car. But when I scrapped off the dirt off it has a cast code of 9779822 but the cast date is c35. This means march 3 1965. So this can not be original to the car.

Does anyone know what 1964 GTO 4bbl with a 2 speed auto came with. I can not seem to find it in the book I have.

 

[tonyskala]

 

[PontiacJim]

OK, interesting on the frame, just would not have guessed that it was factory - kinda amateur looking in fit and finish.

Bushings can be hard to remove, but as old and hardened as they can get, pressing them out may not be the solution. It would have been wiser to use a torch and burn it out, or at least melt it a bit to loosen before pressing.

The 1964 rear end is unique in that it uses the 1 year only smaller bushing and had a shorter upper control arm. I cannot confirm, but the upper control arms may have been designed with an eccentric so they are adjustable (this would change the pinion angle). I supplied a couple pics from the web. These are Chevelle, but it was noted that they were used for other GM A-body cars.

The Pontiac 8.2 10 bolt gray iron cast center housing should have casting #9773369 . However, I found this on Ebay, 1963 cast rear end dated September (I) which makes it a 1964 rear end. It has casting #9773722 . https://www.ebay.com/i/264269389124?chn=ps

If you find a rear end, the 1964 Chevelle also uses the same smaller bushing. The Chevelle forum says Autozone sells the Duralast brand #FB295 bushings, they're $5.99 and they're the right bushings. The FB295 is the front lower control arm bushing for a 73 Camaro with a 1.375 OD.

The PHS documents for your car should tell you the factory rear axle ratio? My info says the W/AC & auto - standard ratio is 3.08. Optional 3.23, and 3.36 optional with the "77" engine only. Without AC on either manual or auto - 3.23 standard ratio on 78 & 79 engine, 3.55 standard ratio on 76 & 77 engine. Other ratios would be optional (3.08, 3.36, 3.90) to include dealer installed ratio's - 4:11, 4:30, 4:33.

:thumbsup:

 

[tonyskala]

So I can find the ratio on my PHS as 3.23. but I can not find in the AMA specifications the cast code on that housing. What I did find is that there are three different castings for the 64. I did not know about the bushing. I will make sure to note that when I buy new bushings.

So on the 1964 as best as I can see there are 3 different housings

9773369
9773722
9779822

I saw that posting on eBay earlier today. His cast code is 1963. I can't tell if it is an I or an L though. I discounted it because the cast was off because I was not sure about it. But now I am not so sure. I have to get this book from my father in law that has more info in it and I am hoping it indicates what the differences are. I am also hoping to run into this guy in San Ramon at this coffee shop tomorrow. He is a regular there and he used to work at the Fremont factory in the 60's and 70's. he has been pretty good about how that factory worked and how they did things.

Thanks for the info you provided.

I got a quote of 480 dollars for a guy to come out and weld the ear back on. I almost fell out of my chair. If it was the correct rear end I might have done it. Although I was reading on the Lincoln welding site welding cast is difficult but not impossible. But they are pretty clear that it really should be used for cracks and attaching two pieces of cast together is not recommended. They also recommend preheating the cast to 600 degree before welding. They have special rods for cast that I did not know existed.

 

[PontiacJim]

So I can find the ratio on my PHS as 3.23. but I can not find in the AMA specifications the cast code on that housing. What I did find is that there are three different castings for the 64. I did not know about the bushing. I will make sure to note that when I buy new bushings.

So on the 1964 as best as I can see there are 3 different housings

9773369
9773722
9779822

I saw that posting on eBay earlier today. His cast code is 1963. I can't tell if it is an I or an L though. I discounted it because the cast was off because I was not sure about it. But now I am not so sure. I have to get this book from my father in law that has more info in it and I am hoping it indicates what the differences are. I am also hoping to run into this guy in San Ramon at this coffee shop tomorrow. He is a regular there and he used to work at the Fremont factory in the 60's and 70's. he has been pretty good about how that factory worked and how they did things.

Thanks for the info you provided.

I got a quote of 480 dollars for a guy to come out and weld the ear back on. I almost fell out of my chair. If it was the correct rear end I might have done it. Although I was reading on the Lincoln welding site welding cast is difficult but not impossible. But they are pretty clear that it really should be used for cracks and attaching two pieces of cast together is not recommended. They also recommend preheating the cast to 600 degree before welding. They have special rods for cast that I did not know existed.

OK, seems you have some info on the rear axle casting codes.

The AMA specs only seems to have gear ratio choices for the GTO - with 4 Bbl the 3.23 as standard gear for both manual & auto. The GTO with tri-power option lists 3.55 as standard gear for both manual & auto. The gear ratio's I first provided came from the GTO Association handbook on GTO specs that they publish.

Cast iron can be welded. I have seen a factory weld repair to a head where the rocker arm stand was fixed. Cheaper to fix a small a small defect rather than cast another head. There are several techniques - heat or no heat. The pieces can be pinned together with a stud prior to welding as well. They make welding rods that can repair cast iron with some being a nickel based rod. From what I have been told, once welded using the nickel rod, the piece cannot be machined as the nickel/weld is extremely hard.

 

[tonyskala]

I dropped both of my rear ends of this am to a fella near me who said he can rebuild the rear end for 600.

When we got them out of the truck and set them side by side I can see the difference between the rear end cast codes 9773722 and 9779822.

It turns out that the ear on the top of the differential with cast code 9779822 has a much larger diameter hold for mounting the rear top trailing arm.

The rear diff that is cast code 9779822 has a smaller diameter hole. Other than that from the exterior they appear to be 100% identical.

It looks to me that the 9779822 were on earlier cars and that Pontiac might have switched over to 9779822. Probably because the larger diameter bushing was better or something for torque. Maybe different gear ratios got you one as opposed to the other. I have an automatic transmission with 3.23 so this was not really a torque monster. Perhaps thats why this car got the smaller bushing rear end. But it looks like there is more meat around the bushing. I would think this added strength to the set up. But since torque twists, maybe a better or larger bushing was required.


https://www.gtoforum.com/attachment.php?attachmentid=119415&stc=1&d=1559941100

https://www.gtoforum.com/attachment.php?attachmentid=119413&stc=1&d=1559941100

https://www.gtoforum.com/attachment.php?attachmentid=119417&stc=1&d=1559941100

https://www.gtoforum.com/attachment.php?attachmentid=119419&stc=1&d=1559941100


A couple of months ago I got a smaller media blast cabinet thinking I would be able to clean these parts on my own. Well the thing works but it takes for ever to clean these parts. And some of my stuff is heavily pitted I have to boost pressure to 260 and it still takes a long time to do these parts. I think I will just get some after market arms and just call it a day. I saw a set of upper and lowers for 470.00. I am getting new springs. My brother in law gave me a nice set of trailing arms upper and lowers. The lowers were already boxed. He said he did not know who boxed them but the weld was sloppy. So I took a grinder to it and made it look nice and neat. I will post some pictures tomorrow.

Now I need to source the bolts for this thing. Every single bolt was rusted and then cut off. I started looking at ARP bolts and had no idea they were so expensive.

 

[PontiacJim]

Interesting. It may be the photos, but the rear center sections look different. The later rear end appears to have a little more length and beef from the center case to where the axle tube is inserted? So similar, but not the same?

 

[tonyskala]

Ok... So I have had most of the suspesion parts for a while now and the body guy doesn't want to do anything until he gets it on the frame. He cant move it around with outthe axels and front end so I need to get this all pieced together.

So My a arms are pitted and I am just going to get new ones. After I push the bushings out and media blast them I figure I would be in it slightly more than just buying new ones.

I found stock ones for 510 shipped both super and lowers.

Sway bar will be reused

Power steering gear box will be rebuilt by a company in LA for 200 bucks shipping not included. Something about reciprocating ball. Need new rag joint.

The links and bearings will be all new. This is all standard stuff

The springs are confusing me. And I need the forum's help

I have nearly stock 389 with iron heads. I see 4 types of springs for the front

500 lbs
250 to 350 lbs
200 to 240 lbs
180 to 230 lbs

I want bone stock but want the car to ride level. The instructions say they may need to be trimmed which runs counter to what I thought. Does anyone one know what the damn thing came with stock. I dont want to spend more money than I need to rebuying this stuff and have no idea how this thing will sit since I have never seen it actually properly assembled.

is a 389 with iron heads considered a big block.

 

[tonyskala]

Ok I think I found it in the AMA Specifications

if anyone ever cares the factory stuff was

Size 11.4 x 3.6

Spring Weight (lbs per in) 225 ....but there is a foot note (b)(e)
b- Except 275 with optional V-8 engine
e- Heavy Duty Springs optional on all models

Rate at wheel (lbs per in) 66 ....but there is a foot note (c)(e)
c- 80 with optional V-8 engine
e- Heavy Duty Springs optional on all models

Design Load (lb @ design height) 1380- 1430 ....but there is a foot note (d)(e)
d- 1635 - 1685 with optional V-8 engine
e- Heavy Duty Springs optional on all models

So I am guessing that stock cast iron block with cast iron heads fall into spring rate of 275lbs with design load of 1635 to 1685

 

[tonyskala]

Ok I am at a cross road where the car will be different on the route I take.

So I have the whole chasis pulled apart and this thing had more grease and dirt on it than I thought. I got it clean enough to see that the entire hardware of the front and rear braking systems was shot. The backing plates were so pitted and rusted. So the rear end builder held off on inserting the axles until I found the backing plates. So when I priced the rear brake system out it was so close to just getting a whole kit pre assembled. So I dropped 430 dollars on a complete set of drum brakes. Those should be here tomorrow. Now the front......

So they are just as bad. The spindle and arm are the only thing useable. So I tried to find a backing plate.... I can't. I can find used ones, but nothing new. Then the drums, springs, shoes, bearings, studs, .... I will be into it for another 400. Then I caught my self.... I could have got a complete system with brake lines for 900. And it would actually stop the car...

I can't do anything about the rears. They will be here soon. But the fronts I think I am just going to go with a disk brake conversion.

It will make this thing easier to drive. But I feel terrible about doing it.

 

[PontiacJim]

You will appreciate the disc brakes up front the first time you have to do a panic stop because some idiot doesn't know how to drive. So, it really does not hurt value per say and what good is trying to stay original if some day the braking just isn't responsive enough and you crash or total out the car?

Just make sure you get the matching dual reservoir master cylinder and related parts for the disc/drum conversion.

 

[tonyskala]

Ok...

Got a complete rear end rebuild drum brake kit. (430 Dollars) This came with everything need to overhaul the system, Will install it tonight. then it is just 2 bushings on top of the differential and the rear end is DONE. He has not told me final cost on rear end rebuild but hopefully it will be right around 600...
New rear coil spings (70 Dollars) and there is a difference for convert and coup. Those rubber bushings that go onto of the springs were like 30 Dollars for the pair on the rear and equally expensive for the fronts.
Got new 250LBS to 300LBS springs for the front. (120 Dollars)
New upper and lower A Arms (500 dollars)
Rebuilt Transmission (1250 Dollars) This dude though I was crazy rebuilding a 2 speed ST300 Transmission. And to boot he seems to have lost the torque converter and I can not find another one.
Sway Bar was sand blasted and just painted.
New Sway bar bushings and stabilizers (30 Dollars)
New Tierods, center link Ideler arm and pitman Arm (300 Dollars)
New Power Steering Gear Box I got so lucky and found one on Craigslist for (200 Dollars) It was New Old Stock....
Front Disk brake conversion with matching Master Cylinder (480 Dollars)
Front and rear shocks (100 Dollars)
Fuel Lines and brake Lines (300 Dollars)

I am missing all sorts of bolts and clips and dont even know what I need yet on this front.

I am kinda of excited to merry up this transmission and engine together. Just have to find this ST300 torque converter. there is one on eBay but I am not entirely sure if it will work for me. Apparently there are differences because Pontiacs are externally balanced. So this Torque converter has external weights and tabs on it.