Convert metric blocks to imperial?

I have several good drawings that I made palettes of the blocks. However, when I insert them they are the wrong size. I believe they are metric drawings. It there any resize procedure I can use to make the blocks insert with the correct imperial sizes, and retain them as such?

Do the block have units assigned, or are they unitless? If they have units assigned, they should automatically scale themselves based on the Drawing Units Insertion Scale. (UNITS)

Nope. Properties on the blocks say unitless.

Well, you have a few choices

1) Select all the blocks and SCALE them accordingly (25.4mm = 1 inch)

2) Explode, scale, and redefine the block in the current drawing so you have a metric and imperial version of the block, each having a scale of 1, but with the metric block being 25.4x bigger.

3) Give your source blocks the appropriate units so they insert at the right scale, then update the block(s) in the current drawing. This is the best option IMO, since it will allow you to reuse your blocks in any drawing, regardless of whether it's Imperial or Metric.