lowering bolt size
Thread Starter
Melting Slicks
Joined: May 2005
Posts: 3,394
Likes: 12
From: Leon Iowa
St. Jude Donor '06-'07-'08-'09
lowering bolt size
I'm going to get some longer bolts for the rear and I have read to use 9/16 or 1/2 bolts. Would the 9/16 be to big to go through the holes? Just wondering wich would be the best size. Thanks
Burning Brakes
Joined: Aug 2000
Posts: 1,132
Likes: 1
From: Morganton, NC, USA
9/16" bolts are very hard to find, especially if you want long ones like 7 inches, so you'll do OK with 1/2"-13 bolts. I believe the stock bolts are threaded 14-2 mm (.551"-.08"), but the bolt shaft is necked down to .500". Soft bolts would probably work as I cannot see how they could be loaded enough to bend or break, but since there are only two, spend the extra couple dollars and buy grade 8. Don't forget to buy two Nylon insert locknuts, they only come in 1/2-13. 
Thread Starter
Melting Slicks
Joined: May 2005
Posts: 3,394
Likes: 12
From: Leon Iowa
St. Jude Donor '06-'07-'08-'09
I just got some 9/16 bolts a little bit ago. I've got mine on but I'm going to take it to a level place to do some adjustments. Oh I found these at John Deere Impliment. I will agree, They are HARD to find.
Burning Brakes
Joined: Oct 2003
Posts: 959
Likes: 12
From: California CA
I lowered mine on the stock bolts with cut bushings. Had plenty of thread and lowered as far as I wanted. Personally, I think longer bolts are a waste of time. The cut bushes will also tighten up the suspension.
Race Director
Joined: Jul 2004
Posts: 10,295
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From: Downers Grove IL
St. Jude Donor '15
Originally Posted by DPG
Where have you guys found the grade 8 bolts. They are so hard to find other than in the vendors at the "corvette tax" price.
Dave
Dave
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Le Mans Master
Joined: Aug 2005
Posts: 7,201
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From: DP(oh you know where) IL
St. Jude Donor '06
Sounds good, thanks. Guess it's back to the phone for me. Oh and if you try and call Home Depot. They didn't even know what a grade 8 bolt was. I hung up right away.
Race Director
Joined: Jul 2004
Posts: 10,295
Likes: 4
From: Downers Grove IL
St. Jude Donor '15
Originally Posted by DPG
Sounds good, thanks. Guess it's back to the phone for me. Oh and if you try and call Home Depot. They didn't even know what a grade 8 bolt was. I hung up right away.
Melting Slicks
Joined: Nov 2004
Posts: 3,495
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From: Paducah Ky
They are quite hard to find. The only place I could even get them ordered was Fastenal. I've had mine ordered for a week now and still not in. None of their stores had the 9/16, or not the ones he pulled up on the computer anyway. He finally found some 14mm that are close to 7 inches.
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
Get 5/8's x 7" bolts w/4 washes and locking nuts ream out your bushings so the 5/8's bolt will fit(spray a little WD-40 on the bushing to slide the bolt through).And you don't have to cut the bushing.I don't think they have to be grade 8 they are a little bigger than stock bolts.I found grade 8 5/8 x 7" bolts,those are hard to find.I got them at SARJO INDUSTRIES,POUGHKEEPSIE,NY(845)454-0070.I think they have any bolt you need.