15x8 wheel 4/6 drop?

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smoothandlow84

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rwjjr

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How is the front end lowered...coils, spindles, control arms or a combination? If you have drop spindles that are more than 2 inches, you may have clearance issues with the lower control arm if its original equipment with those wheels installed.

I was planning on 2.5 spindles and cut a half coil. I may just spend a little more and go with 17s.
 

smoothandlow84

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2.5 inch drop spindles will lead to lower control arm and inner wheel edge clearance issues on most 15" wheels. Some people grind off the effected areas of the lower control arm, but unless you weld in reinforcement plate or gussets the lower control arm strength is compromised. I have a 5 front, 7 rear drop on my 84-87 square (I refer to it that way since only the frame is an 84). I ditched the 15 " wheels that the previous owner installed, replaced the lower control arms that he "modified" and went with 20x8 wheels up front and 20x10 out back. You may end up modifying or replacing the inner front fenderwells for less tire scrub as well even after replacing the oem rubber bumpstops with polyurethane units (I also did that).

Be sure to post pics of your build.
 

rwjjr

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Will do, just trying to get it to daily driver status for now. Start the drop In the next couple weeks.

2.5 inch drop spindles will lead to lower control arm and inner wheel edge clearance issues on most 15" wheels. Some people grind off the effected areas of the lower control arm, but unless you weld in reinforcement plate or gussets the lower control arm strength is compromised. I have a 5 front, 7 rear drop on my 84-87 square (I refer to it that way since only the frame is an 84). I ditched the 15 " wheels that the previous owner installed, replaced the lower control arms that he "modified" and went with 20x8 wheels up front and 20x10 out back. You may end up modifying or replacing the inner front fenderwells for less tire scrub as well even after replacing the oem rubber bumpstops with polyurethane units (I also did that).

Be sure to post pics of your build.
 

MikeB

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Those American Racing wheels have 4.5" backspacing and will more than likely hit the A-arm with dropped spindles. You'd be better off using 15x7 with 3.75" or even 4" backspacing. Even if you can find 8" wheels with 4.00" b/s, I'd suspect you'll have fender clearance issues to deal with.

On another note, I have read on this forum that 8x15 rallys with 4.25" b/s will clear A-arms when using Western Chassis spindles and 1.25" rotors. That may be due to more offset than other manufacturers, or possibly the wheel mounting face of the 1.25" rotor is offset outboard. Hopefully I will know in a few weeks when I install my WC spindles and HD brakes, because I have 15x8 rallys and would like to keep them!
 

smoothandlow84

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That makes sense regarding the rotor thickness and offset issues. I have McGaughy spindles and coils, which may make a difference with clearance. My square (I just found out recently when I replaced the rotors) has heavy duty brakes. The rotor bearings are noticeably larger in diameter than the regular duty rotors and are thicker than normal. It was a discovery that I made only AFTER receiving my cross drilled and slotted rotors. Now if I could just finish my rear disc conversion (this is another reason why I swapped out the 15" wheels for 20"). I think the p.o. swapped out the brakes with those from a diesel suburban as it isn't a camper special truck as far as I can tell.
 

MikeB

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FYI, the inner wheel bearings are different. Outers are the same.

Had all kinds of issues getting the right parts when I installed 86 spindles and brakes on a 69 C10. So I still have notes out the *****!

I don't think GM even started using the light duty brakes until sometime in the the 1980s, but I may be wrong. Anyway, the parts store I dealt with back then (in the Colorado mountains) didn't even stock light duty parts, so had to order them from their warehouse.

Along with 1.25" rotors (and associated calipers and bearings) GM used rear brakes with 2.5" wide shoes. And rear shoe size is sometimes part of the front rotor/caliper description at parts stores.

Brake codes for light duty brakes with 1.04" rotors are JB1 or JB3.
HD codes for 1.25" rotors are JB5, JD3, or JD5.
 

smoothandlow84

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1984 Frame...87 motor and 700r trans
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1500 r10 pavement scraper
Engine Size
350 TBI
FYI, the inner wheel bearings are different. Outers are the same.

Had all kinds of issues getting the right parts when I installed 86 spindles and brakes on a 69 C10. So I still have notes out the *****!

I don't think GM even started using the light duty brakes until sometime in the the 1980s, but I may be wrong. Anyway, the parts store I dealt with back then (in the Colorado mountains) didn't even stock light duty parts, so had to order them from their warehouse.

Along with 1.25" rotors (and associated calipers and bearings) GM used rear brakes with 2.5" wide shoes. And rear shoe size is sometimes part of the front rotor/caliper description at parts stores.

Brake codes for light duty brakes with 1.04" rotors are JB1 or JB3.
HD codes for 1.25" rotors are JB5, JD3, or JD5.



Yeah...I know that the outer bearings are the same. I just realized that when the cross drilled and slotted rotors arrived, the inner races and bearings were too small. They wouldn't slide over the spindle and seat properly. I ended up returning the new rotors and the company that I ordered from swapped out for the larger units. They also informed me that there were two options for the rotors listed. Its nice knowing that I have the correct parts AND that they are heavy duty.

If I still had my hydraulic press, it would not have been an issue. I could have just swapped out the races and bearings. It was easier to just send the rotors back.

Just one more "mystery item" that has been discovered during this build. With so many interchangeable parts, replacing wear items gets crazy at times.
 
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