[JJR]

Here is what Hollander says will work for an 86 1/2ton Suburban lower control arms:

BLAZER/JIMMY (full size) 73-78
BLAZER/JIMMY (full size) 79 exc. 6.50x15 tire and 10x15 tire
BLAZER/JIMMY (full size) 80-82
CHEVROLET FORWARD CONTROL 73 10 Series
CHEVROLET PICKUP TRUCK 73-78 10 Series
CHEVROLET PICKUP TRUCK 79 10 Series; exc. 6.50x15 tire and 10x15 tire
CHEVROLET PICKUP TRUCK 80-88 10 Series
CHEVROLET VAN 73-74 10 Series
CHEVROLET VAN 73-74 20 Series
GMC FORWARD CONTROL 73 1500 Series
GMC PICKUP TRUCK 73-78 1500 Series
GMC PICKUP TRUCK 79 1500 Series; exc. 6.50x15 tire and 10x15 tire
GMC PICKUP TRUCK 80-87 1500 Series
GMC VAN 73-74 1500 Series
GMC VAN 73-74 2500 Series
SUBURBAN 73-78 10 Series
SUBURBAN 73-78 1500 Series
SUBURBAN 79 10 Series; exc. 6.50x15 tire and 10x15 tire
SUBURBAN 79 1500 Series; exc. 6.50x15 tire and 10x15 tire
SUBURBAN 80-88 10 Series
SUBURBAN 80-91 1500 Series

I am sure someone has a set in your neck of the woods. Junkyards would probably get around $50-60 each for them or if you have a U-Pull-It type place you can get them for $15-20 each. Hope you get a set.