Does it matter which springs you remove

Yikes, I never heard of anyone removing a spring from a reverb unit before. Why don't you just turn it down?!

 

You're better served getting the proper "2 spring" (actually a 4-spring) tank. But if ya gotta chop, chop the middle one (pair) in your 3 (6) spring tank.

There are quite a few people (particularly on FleaBay) touting the 6 spring tank as an upgrade for your Fender.

Don't do it -- unless you're willing to mod the reverb circuit these tanks will have wayyy too much dwell. They work great in a reverb circuit with a dwell control though

PS: He can't turn it down because all his amp has is a mix control. The problem is the strength of the driving signal - fixed in most amps.

 

FWIW, the standard tank for a Fender is a medium delay.

When you go looking for replacement parts this link might help:

http://www.accutronicsreverb.com/prodspec.htm