BUILD THREAD my 1980 Grand Prix w/BBC 454 build thread

[theoldsone]

Awesome build. Progress is looking good. Seems like the FiTech EFI systems are a big hit. Everyone is running them. Eventually I plan on buying a kit too. Can't wait to see what that 454 will look like in there.

 

[mr evil]

Great thread, well written and fun to read.....looking forward to updates as you move forward!!

 

[454GrandPrix]

This morning I decided to look at the rear brakes. Specifically, I want to remove the Fox body parking brake cables from the car and see if I can make the Grand Prix cables interface with the Ford brakes. The car was already parked on my concrete pad next to the house, so all I had to do was lift the tail and set it on jack stands. Once the stands were in place, I lowered the jack and allowed the axle to reach full droop. As I always do, I spent a few seconds taking a final look at the jack stands and even jiggled the car a bit to ensure everything was steady.

Just as I finished, I noticed--with alarm--that there was a puddle rapidly forming under the right rear wheel. I am a bit OCD about keeping my concrete unstained, so I quickly ran into the garage, grabbed some kitty litter and a paper towel, and ran back to the car to absorb the spill. "How could I have compromised the hydraulic system?" Before I could look into it, I noticed with even more alarm that a matching puddle was also forming under the left rear wheel. What the hell?!? I ran back inside for another scoop of kitty litter and another paper towel, then returned to address this second puddle. With that done, I looked up to find the source of the leaks. It didn't take me long to figure it out:

Gee. I guess driving with the taller springs didn't make the ancient stock-length shocks very happy, and as soon as I put the axle at full droop they both burst. Ironically, just last night I was doing some casual internet research for new shocks. I guess I'll be buying them sooner than expected.

 

[454GrandPrix]

I carefully studied KYB's web site and their Gas-A-Just shocks. When plugging in my car, they said a stock replacement is item #KG5548. These shocks have a compressed length of 12.95" and an extended length of 20.83". I obviously needed something that could allow for at least two more inches of extension. I quickly found item #KG5508, which shares the same general design; it has a compressed length of 14.53" and an extended length of 23.78". That sounded about perfect, so I ordered a pair.

I installed them yesterday. This required a run to Ace Hardware since the lower bolts provided by KYB were not long enough to fully engage the nut. Other than that little hiccup, it was very straightforward.

Now the tail end isn't as bouncy as it had been. (Surprise!) I can't wait to do the front end to match, though that probably won't happen until after the engine swap.

 

[MrSony]

I carefully studied KYB's web site and their Gas-A-Just shocks. When plugging in my car, they said a stock replacement is item #KG5548. These shocks have a compressed length of 12.95" and an extended length of 20.83". I obviously needed something that could allow for at least two more inches of extension. I quickly found item #KG5508, which shares the same general design; it has a compressed length of 14.53" and an extended length of 23.78". That sounded about perfect, so I ordered a pair.

I installed them yesterday. This required a run to Ace Hardware since the lower bolts provided by KYB were not long enough to fully engage the nut. Other than that little hiccup, it was very straightforward.

Now the tail end isn't as bouncy as it had been. (Surprise!) I can't wait to do the front end to match, though that probably won't happen until after the engine swap.

Love the stance for the back of the car.... do you know what springs are in there?

 

[454GrandPrix]

Love the stance for the back of the car.... do you know what springs are in there?

Oh, crap--I could have sworn I mentioned that in this thread. I just re-read it to verify that I had not. My apologies.

When I first installed the Ford axle, my friend welded one coil spring perch about 1.5" too far to the outside. Oops. I took it right back to him to have it torched off and relocated to the proper spot. Doing so would require removing the coils, so I decided now was the right time to replace my tired old stock ones with stronger, taller ones that could handle the weight of the big block & 4L80E transmission. (I didn't replace the coils at first because I wanted to see where the ride height ended up with the new axle.)

Doing lots of internet research, it seemed the Moog 5391 coils would give me a bit of rear-end lift. They can also handle more weight thanks to their higher rate, so I decided to give them a try. In my case, I got 2.0" of lift at the rear tire. I'm sure it will squat a bit more after the driveline swap, but I'd be lying if I said I didn't like the way it looks already.

 

[MrSony]

Oh, crap--I could have sworn I mentioned that in this thread. I just re-read it to verify that I had not. My apologies.

When I first installed the Ford axle, my friend welded one coil spring perch about 1.5" too far to the outside. Oops. I took it right back to him to have it torched off and relocated to the proper spot. Doing so would require removing the coils, so I decided now was the right time to replace my tired old stock ones with stronger, taller ones that could handle the weight of the big block & 4L80E transmission. (I didn't replace the coils at first because I wanted to see where the ride height ended up with the new axle.)

Doing lots of internet research, it seemed the Moog 5391 coils would give me a bit of rear-end lift. They can also handle more weight thanks to their higher rate, so I decided to give them a try. In my case, I got 2.0" of lift at the rear tire. I'm sure it will squat a bit more after the driveline swap, but I'd be lying if I said I didn't like the way it looks already.

Thanks a bundle. So the 454/4L80 are NOT in the car right now, correct? And what springs are up front if you know?

 

[454GrandPrix]

So the 454/4L80 are NOT in the car right now, correct?

Correct, still running the Buick 231.

And what springs are up front if you know?

Whatever Pontiac installed back in 1980. Same goes for the front shocks, too.

 

[454GrandPrix]

Yesterday was my day off work. My co-workers have been very vocal about me removing the stock V6 & transmission, so I wanted to work toward that goal. I began by spending hours cleaning and organizing my garage in an attempt to make enough space to fit both an engine hoist and the Grand Prix in there. I did manage to free up a lot of space, but by then it was late enough in the day that I didn't want to start ripping into the engine bay...

... so I decided to install a stereo instead. I was tired of staring at the gaping hole in the dash, and a month or so ago I had already installed a pair of 6x9s under the rear package shelf. The former owner had hacked up all the factory wiring at the stereo, so I had to essentially run new wires for everything from scratch. After a bit of effort, I finally had music.

I don't know where I'd mount front speakers, so for now I'll just stick to the two rear ones and call it good.

Oh, and now I need to repair my cracked dash bezel so I can reinstall it. 🙂

 

[GP403]

Armored Saint. There's a name I've not heard in a long time. You win the internets for today.