1987 Grand Prix front springs for Pontiac v8 with air?

[BYoung43]

My GP came with a 350 Chevy and since I have my 400 Pontiac engine in the car now, I need new front springs. Is there any real difference in front weight from a 1978 GP to an 87 GP? The 78 would also have an 80 LB lighter 301 to start with. The heavy duty for the 78 are calling for Moog 5610.

[http://www.moog-suspension-parts.com/proddetail.asp?prod=MOOG-5610]

I'm thinking those might not be "heavy" enough. I was looking at useing the springs for a 1981 GP with the olds diesel.

[http://www.moog-suspension-parts.com/proddetail.asp?prod=MOOG-5642]

The free and installed heights are almost identical, the LbS per inch is only 4 LBS lighter, but the "load" is 110 LBS heavier. I want to run A/C and the car will be drag raced a LOT, so I wouldn't mind at all haveing the front and inch to an inch and a half higher than the rear for good weight transfer to the rear. The rear has stock springs now and sits quite nice, but as the front comes up, the rear will go down. The front sits about 2 inches lower than the rear right now with the old wore-out Chevy springs. If it's too tall with the diesel springs, I could always go down 1/2 a coil at a time, but I'd rather "hit it" right off with alot of disassebly. What have you guys with this rig used with success?

Brad

 

[pontiacgp]

If I were you I'd be asking shotgun these questions....he runs a GP and he knows alot when it comes to a drag racing set up. You might get most of your questions answered and some ideas by looking up a few of his posts..

 

[Bonnewagon]

Yes, Shotgun is the one to speak to. I ran a 400 in my Malibu and used 77' TA springs with 3/4 of a coil cut off. Very stiff and raised the car about 2-3" in the front.

 

[SafariWagon]

81 lemans wagon 400 Pontiac with air. I am running Moog 5662 with 2/3 of a coil cut off for a lowered look. probably pretty close to stock height with no modifications. The Moog 5668 is not enough. Sits too low. I have a set for sale if you want to try though........... :lol:

 

[79GP6.6L]

I've run stock 301 springs with a 400 in the past. The ride height was good but the front suspension bottomed out easily.

Currently I'm using the front coils from an 89 Formula in my GP, because I had them sitting around and figured I would give them a try. They handle the weight if the 400 easily, but the front of the car sits just a bit too high for my liking. One of these days I'll try cutting off 1/2 a coil or so and see how that looks. If I can get the front to sit a bit lower, I will be happy with the Formula springs.

 

[Bonnewagon]

I would advise to cut 1/4 coil at a time. It makes a big difference, and you may overdo it. I know it's a pain to cut-check-cut but you can allways cut more, but you can't put it back on.

 

[79GP6.6L]

Thanks, I'll do that. I've never had to cut coils before. I figured anything less than 1/2 a coil would be to little to make a difference.

 

[Bonnewagon]

What I do is drill out the shock mounting hole at the top and run the spring compressing tool down through it. I then use the fingers with the threads on the bottom to compress the spring up into the tower. This way I can just drop the lower control arm out of the way and cut the spring with a cutoff tool either air or electric. That way it gets cut fast and doesn't build up enough heat to damage the temper of the spring. A torch is a no-no, it will ruin the spring. Depending on how far the bottom of the spring now is from the gutter in the arm after lowering it into the A-arm, I can usually get a prybar to work the spring around so the tag end is located properly in the gutter with the 2 drain holes. As allways, treat a compressed spring like dynamite and use a small safety chain to restrain it to the frame in case it gets away from you.

 

[rhollrah74]

diesel wagon springs worked very well for me. Also have 2" lower spindles on the car with 18's.

 

[BYoung43]

Moog 5610 work GREAT for a 400 Pontiac engine in my 87 Grand Prix! Just wanted to drop a post here in case someone meanders along with the same question. This is the spring number that comes up most of you look for front springs for an 82 GP with the Olds diesel motor.

Brad