pruning new blackcurrant bushes

[gan heather]

I picked up 2 really good-looking blackcurrant bushes today (for only £2!). I plan on planting them either Sunday or Monday. The directions say that after planting, I should prune back the stems till they're only 2 inches long. Is that correct? The bushes are about 2 feet tall and that seems like a lot of pruning for a newly planted bush.

Anything else I should keep in mind when planting them?