Virnig lists their 67.5 low pro as 13.1 struck and 15.7 heaped, they have several bucket types, if you find one that matches yours struck, then the heaped capacity would be vary close.
http://virnigmfg.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=35&category_id=9&option=com_virtuemart&Itemid=77
Ken
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Low Profile Dirt Buckets (Standard)
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Features:
Standard and Heavy Duty models in various widths
Low profile and extended bottom for better visibility of cutting edge
Rolled and grading bend profiles available
3/4" x 6" edge with holes to accept bolt on edge
Benefits:
Excellent visibility of bucket edge
High strength steel construction
Standard buckets recommended for loaders with operating capacities less than 2400 lbs.
MODELS
DHV60EX/ RDHV60EX/ DHV60EX-GB
DHV66EX/ RDHV66EX/ DHV66EX-GB
DHV72EX/ RDHV72EX/ DHV72EX-GB
DHV78EX/ RDHV78EX/ DHV78EX-GB
DHV84EX/ RDHV84EX/ DHV84EX-GB
Overall Bucket Width (Inches)
61.5
67.5
73.5
79.5
85.5
Bucket Depth (Inches)
34.6/34.6/35.8
Bucket Height (Inches)
20.5
Struck Capacity (Cubic Feet)
11.9
13.1
14.4
15.7
17.0
Heaped Capacity (Cubic Feet)
14.3
15.7
17.3
18.8
20.4
Approximate Weight (Pounds)
460/490 /490
490/525/ 525
575/555/ 555
620/600/ 600
655/635/ 635
*Dirt Bucket/Rolled Dirt Buckets/Dirt Buckets with Grading Bend
View Full-Size Image
Low Profile Dirt Buckets (Standard)
Ask a question about this product
Features:
Standard and Heavy Duty models in various widths
Low profile and extended bottom for better visibility of cutting edge
Rolled and grading bend profiles available
3/4" x 6" edge with holes to accept bolt on edge
Benefits:
Excellent visibility of bucket edge
High strength steel construction
Standard buckets recommended for loaders with operating capacities less than 2400 lbs.
MODELS
DHV60EX/ RDHV60EX/ DHV60EX-GB
DHV66EX/ RDHV66EX/ DHV66EX-GB
DHV72EX/ RDHV72EX/ DHV72EX-GB
DHV78EX/ RDHV78EX/ DHV78EX-GB
DHV84EX/ RDHV84EX/ DHV84EX-GB
Overall Bucket Width (Inches)
61.5
67.5
73.5
79.5
85.5
Bucket Depth (Inches)
34.6/34.6/35.8
Bucket Height (Inches)
20.5
Struck Capacity (Cubic Feet)
11.9
13.1
14.4
15.7
17.0
Heaped Capacity (Cubic Feet)
14.3
15.7
17.3
18.8
20.4
Approximate Weight (Pounds)
460/490 /490
490/525/ 525
575/555/ 555
620/600/ 600
655/635/ 635
*Dirt Bucket/Rolled Dirt Buckets/Dirt Buckets with Grading Bend