cudaspaz
Well-Known Member
I mentioned before that my high arch ss springs required 1.5" lowering blocks to get the car to ride at an acceptable height since they were jacked wayyyy up there with no blocks installed.
After a few years the springs have settled substantially and during this whole time with the 1.5" blocks I had a lot of axle wind up under heavy acceleration which caused a lot of thumping under the car.
I finally yanked out my 1.5" blocks and replaced them with mancinis billet aluminum 3/4" blocks.
They came with the correct size u bolts And nuts wich was great but I had problems with the blocks.
It seems that nobody took into account the size of the spring perch alignment holes as the pins at the top of the blocks were too large in diameter.
My choices were to bore the spring perch holes larger which would mean yanking out the rear end or file the pin diameter down on the lowering block guide pins.
Also the blocks did not sit flush on the springs as it seemed like the bottom side holes on the blocks were not drilled deep enough.
I put the blocks in my drill press and was going to drill them deeper,when I found that the center pins were pressed into a hole, not machined and they actually,moved rather easily,as my drill press pushed them further out of the hole like A shop press would....so I did not have to drill.
I just pressed the pins to the proper adjustment to allow them to sit flush on the spring locating pins.
Lastly I had to file the portion of the block pins that was sticking out( the part that goes into the hole on the sping perch) to allow it to fit.
I put the blocks in my vice and hand filed them all around the perimeter of the pin and then used one of those gnarly scale remover wheels on a die grinder all around the pin to keep it smooth and uniform between hand filing the pins.
When all was said and done, the blocks are installed perfectly, the car sits with a nicer rake and best of all I took it out for a few shake down runs up the street, retorqued my U bolts, then once I was satisfied all was well I took it out for a few hole shots and some hard launches and shifted through the gears hard to see how it felt.
Well, the results were amazing as I no longer have my axle wrap up and the thumping is gone.
The car accelerates much smoother and the *** end is at a perfect ride height.
Moral of the story?
Too tall of a lowering block will give you too much axle wrap up, and probably wear the springs out quicker.
Secondly?
I really friggin hate having to modify brand new parts but but I'm happy that it all worked out, but keep in mind that Mancinis 3/4" billet aluminum lowering blocks may need modified to fit your spring perches.
Oh, I also dripped some red loc tite on the underside of the blocks where the pins are pressed in hoping that the pins won't slide in their seat under load/vibration.
Don't know if I had to do that but I did anyways.
A few more minutes of forethought and those blocks could be sold as a ready to install part.
I don't know if they built them that way so the pin depths could be set as needed depending on locator pin depth but the pin diameters definitely could have been machined to the same diameter as the 1.5" blocks they sell.
Sorry for the rant.....just a heads up in case someone else runs into this.
That all being said, I thoroughly enjoy receiving new toys at my door step from Mancini racing.
After a few years the springs have settled substantially and during this whole time with the 1.5" blocks I had a lot of axle wind up under heavy acceleration which caused a lot of thumping under the car.
I finally yanked out my 1.5" blocks and replaced them with mancinis billet aluminum 3/4" blocks.
They came with the correct size u bolts And nuts wich was great but I had problems with the blocks.
It seems that nobody took into account the size of the spring perch alignment holes as the pins at the top of the blocks were too large in diameter.
My choices were to bore the spring perch holes larger which would mean yanking out the rear end or file the pin diameter down on the lowering block guide pins.
Also the blocks did not sit flush on the springs as it seemed like the bottom side holes on the blocks were not drilled deep enough.
I put the blocks in my drill press and was going to drill them deeper,when I found that the center pins were pressed into a hole, not machined and they actually,moved rather easily,as my drill press pushed them further out of the hole like A shop press would....so I did not have to drill.
I just pressed the pins to the proper adjustment to allow them to sit flush on the spring locating pins.
Lastly I had to file the portion of the block pins that was sticking out( the part that goes into the hole on the sping perch) to allow it to fit.
I put the blocks in my vice and hand filed them all around the perimeter of the pin and then used one of those gnarly scale remover wheels on a die grinder all around the pin to keep it smooth and uniform between hand filing the pins.
When all was said and done, the blocks are installed perfectly, the car sits with a nicer rake and best of all I took it out for a few shake down runs up the street, retorqued my U bolts, then once I was satisfied all was well I took it out for a few hole shots and some hard launches and shifted through the gears hard to see how it felt.
Well, the results were amazing as I no longer have my axle wrap up and the thumping is gone.
The car accelerates much smoother and the *** end is at a perfect ride height.
Moral of the story?
Too tall of a lowering block will give you too much axle wrap up, and probably wear the springs out quicker.
Secondly?
I really friggin hate having to modify brand new parts but but I'm happy that it all worked out, but keep in mind that Mancinis 3/4" billet aluminum lowering blocks may need modified to fit your spring perches.
Oh, I also dripped some red loc tite on the underside of the blocks where the pins are pressed in hoping that the pins won't slide in their seat under load/vibration.
Don't know if I had to do that but I did anyways.
A few more minutes of forethought and those blocks could be sold as a ready to install part.
I don't know if they built them that way so the pin depths could be set as needed depending on locator pin depth but the pin diameters definitely could have been machined to the same diameter as the 1.5" blocks they sell.
Sorry for the rant.....just a heads up in case someone else runs into this.
That all being said, I thoroughly enjoy receiving new toys at my door step from Mancini racing.
