There is a good article in the June RMC about decoder installation. The target loco is a Bachmann H-16-44, but the information is generally applicable to split-frame engines.
Rusty
Jim Banner has this at his site.
http://www.members.shaw.ca/sask.rail/dcc/tmaster/tmaster.html (http://www.members.shaw.ca/sask.rail/dcc/tmaster/tmaster.html)
This is not specific to the topic, but when someone asks about installing a decoder in a certain locomotive, I always check the TCS site. Mouseover "Installation Pictures" on the left menu. The site is rapidly expanding, currently being remodeled.
http://www.tcsdcc.com/
Several members use TCS decoders, and have reported good performance.
Regards.
That is a great site that shows pictures of just about every installation, besides HO there are N, Z and O gauge installs