70 GTO Build thread
 

I picked up this non running GTO in Lake Havasu City, AZ. Its been sitting outside since 2007. The sheet metal is dent free and no rust at all. Lake Havasu City is very dry area of AZ.
I will be doing a resto on it and will post pics of progress as I go.
I will be looking for advice and opinions as I go also. Thanks.

Congrats...that looks like a great starting place.

More info on the specs and plan??

Nice. No better region to get a car from.

Its a 400 auto with/AC. Original color was Palisade Green. Someone painted it silver using very low quality paint. The motor in it is a 455. I was on my way to Nevada when I saw this for sale. I didn't have any reference books with me. I knew the motor would be a Y something but wasn't sure. I looked under the hood and saw the 13 400 heads and a YC stamp on the motor. I figured it was correct. The woman selling it didn't know anything about the car.

When I got it home I realized it was a 1971 455 block with the 400 stuff bolted to it. Oh well. I do have a 1970 YS 400 block sitting in my shed.

Im pretty sure I think I am going to paint it Atoll Blue since its a non matching car and Im not a big fan of Palisade Green. It has a black interior so I can paint it any color I want.

Wonderful find, Bruce.

If you don't have a home for that 71 455 short block, I may have some interest. I'm always on the lookout for certain date range 71 455 blocks.

PM me if you like. :)

Ok I will let you know if I decide to sell the 455 short block.

Pulled the front bumper and started sandblasting. The desert preserves the sheet metal but its murder on endura bumpers. This ones going to need a lot of flexible filler.

Ive been out of action lately due to a bad back. Ive been working on the the front bumper. Here is about 25 hours total so far. Ive been using Polyvance flexible filler and am very happy with it. It feathers real nice and is very flexible and it sticks to the Endura bumper real good.

Can anyone post a close up picture of the very center of the front bumper where it meets the hood? The line on this one is pretty much completely gone and I need something to go on so I can reshape that part of it. Thanks.

Had to get a pic with a good perspective of the point.

Awesome! Thanks!

Looking forward to watching the rebuild as you progress, get what you can done now as the heat of the summer will be upon us soon.

Im lucky enough to have this shop equipped with A/C.
Right now I have to wait until Friday when a buddy of mine can help me fit the front bumper to see how far off my bodywork is. A 70 GTO bumper is Heavy! I thought 68/69,s were heavy. These things are monsters.
In the meantime I sandblasted the bumper brackets and painted them. I was happy to see there was no pitting.

A/C for your shop is a nice bonus for sure! :)

When we put the nose on my 70 gto we jacked the front off the ground by the cross member. Install the nose and then let it back on the ground onto the suspension. It would move the nose tighter to the fender. Surprising how much things move around by just jacking the front of the car off the ground. The engine was in the car.Getting the nose where I was content was alot of moving the nose left and right,,,,up and down. And still isn't that great as far as being even and flush everywhere. The nose shrunk length wise over the years. And you can only bring the front of the fenders together just so much because the hood is a certain width. I'm not a body guy and it drove me nuts. I had to walk away and regroup a few times.

Ive had the same issues with a 69 GTO that I did. The bumper was in bad shape like this one. I took it off the car and patched it up and forgot about it. When I went to bolt it up it was way off and had to be redone. With this 70 I left the car intact and patched up the bumper and did a test fit. I was lucky this time and everything lined up so now Im doing final touch up and primer. These things are very tricky. I almost decided to look for a better one until I saw the price people wanted for a decent one. Ive got around 40 hours in this one so far. I couldn't imagine what a body shop would charge to fix it right.

Finally done with the bumper. Lots of priming and blocking. Filling pinholes. etc,etc. Next up is the hood.

Started to sand on the hood and noticed it has 2 layers of factory green under the silver. The rest of the car has 1 green coat and one silver. I think I found out why. A dent on the hood scoop that was filled with bondo. Im wondering if the hood wasn't damaged in shipping and the dealer fixed it with bondo and a repaint. Im pretty sure I can pound that out from the bottom side.

The hood is almost done. My Air Compressor broke down so bodywork is on hold till a replacement part comes in. Started pulling the front sheet metal off. Those nut clips or whatever they call them were breaking like crazy making it a real PIA. One thing that is good is there is no rust in the cowl area or lower fender. The factory Palisade Green looks pretty good. Not a bad color really.

Bruce, Nice work so far! I do like Palisade green, but I'm a bit biased. Following your progress.

Dennis

Looks good,,,,following also.

Looks good! If my car was a matching #,s car it would get the Palisade Green paint. I just love the Atoll Blue though. I found this pic of an Atoll Blue 70 on the internet.

Does anyone know what this round gizmo is that is bolted to the passenger inner fender? It was mounted behind a vapor canister. It has what looks like a vacume port. Thanks

It's a vacuum resevoir to keep the air conditioning controls and vents from changing under low vacuum conditions, should have a one way valve plumbed in the feed line from the engine.

Thanks for the info. 1970 must be the first year for that reservoir because I have done 2 different 69,s with air and they didn't have one.

What??? It's a carburetor choke vacuum source. Page 6-25 in the '70 GTO assembly manual.

Looks pretty close to early silver leaf green.Like it.Tom

Well it sure as hell is ��. Actually the carb has a nipple that is the source for the choke pulloff, and the pulloff has a second nipple that goes to that ball. It would seem all vacuum would be lost as soon as the engine is turned off. So, why is it used ??
I've seen that used as a ac syst vacuum resevoir my whole wrenching career. Why it is set up like that makes not a lick of sense to me.

I apologize for giving the incorrect info.

John

The engine/trans ready to pull. It comes out tomorrow when I can get a buddy over to help. The engine is pretty dirty and looks like it was run for many miles. Im curious to see what the previous owner did to be able to run high compression 400 heads on a 455. That would be close to 12:1 compression. Im hoping the pistons were dished. Hopefully he didn't run the high compression by backing off the timing. Retarded timing is bad for the engine. On a good note I pulled the tranny pan and it was very clean inside. I should have the engine torn apart by Monday. I will post pics.

I got the engine partially torn down. The 13 heads look great. Thick valve margins. No signs of valve recession. Some of the nicest Pontiac heads Ive seen in a while. The block is standard bore 1973 455. I was wrong about it being a 71. I am shocked to see flat top factory cast pistons inside. With all that compression the previous owner must of ran leaded race gas. As you can see from the gunk in the valley area he wasn't too good on the oil change schedule. I will pull the crank out in the next day or two to see how that looks.

I may have to bring my bumper down to you. That was a great job! I have new std pistons if it can be honed

Thanks. Im pretty sure the block will need to be bored .030. I happen to have a set of TRW forged .030 pistons from a previous build on hand to use. Im still debating whether to build a YS 400 with the 13 heads or stick with the 455 and run 6X heads that I have. Im leaning toward the 455 because I already have pistons for it and the price of new forged pistons for the 400 range from 600-700 bucks. Crazy!

Don't be afraid of the 400 either. I think i went on a Piston buying binge a couple years ago. Have 400 .030 pistons too. And 428 and 421 SD and...........

Do you have any dished 400 pistons?

I think I found out why this car was parked years ago. Most of the lobes on the cam are wiped out. The metal from that got into the bearings and scored them up. They overheated too and lost their crush. The crank will have to be magged to see if its cracked before I can make a decision on what motor to go with.

Probably wiped cam result of lack of oil changes (evidenced by gunk in valley)

Got the crank back from machine shop. It magged good, It looks like I am going with the 455. More cubes is never a bad thing. Right? Ive been pulling the interior out. The part I hate the most. I would rather pull a motor any day over an interior. The interior was not that bad. Seats are actually useable. The fronts have a small tear here and there. They will get recovered anyway. The only thing that had me scratching my head was the amount of rust on the shifter. Everything else is clean and rust free. The previous owner must have spilled a bunch of sodas on the shifter.

Its been a while since I posted progress. Ive been doing mostly boring stuff like disassembly. I am working on fenders and valences. I took them to a shop that does media blasting to make life a little easier. A lot of dings and dents were revealed. First pic is bare metal with skim coats of Bondo on the problem areas. Second pic is the same fender shot with self etching primer. Next is the fender shot with high build primer. I like this primer because it goes on somewhat glossy so you can see all the bad spots.

Subscribing!

I wanted Atoll Blue too, but saw some in person, and wanted a little more depth and flake. I ended up with a 2015 Caddy color, Opulent Blue. I like it, was exactly what I was looking for. Think I listed the paint code on my build thread.

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That Opulent Blue is a great color..... Now you have me thinking..

Making a little progress. Im very slow at bodywork. Doors are done. The driver side was nice with very little dings but the passenger side was a bit of a mess. Lots of parking lot dings and creases. The fenders were the same way. Driver side was easy. Passenger side was like the door. Lots of dings.

I ran out of high fill primer. I went to order some more and everyone has the primer but not the hardener. They are telling me next month. I sandblasted the hood scoop inserts from this 70 and a pair I had laying around for years. I don't know where they came from but someone opened them up and did a sloppy job. I noticed on the bottom side the 70 inserts have only 2 hold down studs but the unknown ones have 3 hold down studs. The 70 hood only has provisions for 2.

Maybe they are repops? Or a Canadian car?

Make sure they fit properly would be my suggestion, if you plan to use them.

Nice thing about using a later OE color, is you can easily find the paint/code if by chance you need a touch up.

Also, colors that are more than X number of years old either cost more, or are never the correct shade.

You can stalk dealer parking lots, and see the color in person on a car, which removes a lot of guessing/risk.

A lot of the blues have purple in them, which is a personal 'erk' to me.

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.I thought about the issues you brought up and they are good points. The only thing I worry about, as you mentioned earlier about your color, is there is more metallic in it. The more metallic there is the harder it is to spray without getting streaks or zebra stripes. Im not ultra experienced in shooting metallic. Im still on the fence but your right, the new colors pop much better than the original colors from back then.

Pretty sure the paint my painter used is a 1-stage, and my understanding they are much easier to spray metallics. But maybe someone else can chime in on this. I wouldn't think the factory would want to run the risk of spray anomalies if it was a difficult process, but could be mistaken on that.

EDIT: Here's an example of the color in the sun:


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While I am waiting to get more primer in to finish the bodywork I decided to work on the engine by porting the 6X4 heads I will be using.

The intakes on the 6X heads are actually a little bigger than the standard Fel Pro gaskets. I had to open up the gaskets a bit.

Edelbrock P4B just out of the sandblaster. I picked this manifold up many years ago for 40 bucks when everyone thought they sucked. Everyone was wrong. Its a fine manifold. The runners are identical to a stock 4BL manifold that everyone thinks is great. Its only difference is its flanged for a Holley square bore carb. I will be using a Holley 750 Double Pumper.

Nice! I suggest etching and painting it with engine paint, your call on that.

I've seen people have desirable results running that intake, they only give up a little once you go beyond a certain power level. Your butt will never feel a difference between it and an OE one.


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Are you using the 1233 RA4 intake gaskets?