Rear coil springs in relationship to ride height

[1970 SCCA Junkie]

Recently purchased a 2007 GT 4.6 manual trans, previous owner stated the car had been lowered an 1" to a 1 1/2" no other modifications other than a CAI that did not require a tune and Borla S Type mufflers. I purchased the car to be a daily driver but wanted to pay tribute to the 1970 SCCA trans am series mustangs. The first thing to go was the Borla's and over the axle pipes, I added to 12" Cherry Bombs and approximately 21" of 2 1/2 " exhaust pipe exiting out in front of the rear tires on each side. I tucked the exhaust up as close as I could but could use that 1 to 1 1/2 inches of clearance. If I go back to original springs just on the rear do I need to be concerned with pinion angle? I have replaced the rear shocks and I told the wife people will stop asking who's got the mustang with all the stripes and decals, eventually. I did search for posts pertaining to my situation and if I missed it I apologize in advance.

 

[07 Boss]

If you are putting it back to stock ride height you should be good to go in theory. What is your angle now? I would think that with stock rubber bushings in there there is quite a bit of deflection so I wouldn't worry too much about it.

 

[FredB66]

That's correct. Returning the rear to factory ride height will return the pinion angle to factory as well. Keeping the lowered front doesn't change the pinion angle since the angle is related to the driveline/chassis, not the ground.

 

[86GT351]

Shoulod have no issues going back to stock. I have to ask though......Cherry Bombs?

 

[1970 SCCA Junkie]

Thanks for the responses, I appreciated your time and knowledge. I'm going to Mendards tomorrow to see if I can score an angle gauge so I can do a before and after measurement with the spring swap. I rolled with the Cherry Bomb glass packs as a shout out to my late father. We had a 65 Mustang 289 manual trans back in my early years before I could drive and dad put Cherry Bombs on it so I thought I'd follow suit. Probably where I got the SCCA bug. He loved cars and racing. Thanks again to one an all.

 

[JC SSP]

Try to post pics and audio clip.

 

[Autokyrios]

Without adjustable suspension, those angles aren't changed for the drop, so putting it back to stock height will automatically bring the pinion angle back to normal. You can't really change the pinion angle to correct for lowering if you have no way to adjust the orientation of the rear axle (adjustable LCA's/UCA, mount points, etc.). Sounds like none of that was done so the car's been basically at the wrong angle the whole time.

As for the exhaust changes...it's not my ride so I don't care...but IMO the true, beautiful sound, sound is what the motor makes. Will it be loud an annoying? Yes. Will it sound good? No.

 

[1970 SCCA Junkie]

I hope the request was for pics of the exhaust and sorry it took me so long and sound clip to follow. After taking pinion angle measurements the consensus was correct and they are within 2 degrees of each other. I didn't take a step back pick of the car as it still needs to be decaled and looking for the needle in the haystack chrome bumper covers that sad to say have not been produced in 10 years. For the look I'm going for I think they would be a nice touch. Thanks again to all who replied.