mduncan31- Go to DirtOval.com. The BEST RC Dirt Oval site! Awesome people that are willing to help out the new guys that are getting into the sport.
My advice is it depends on the type of track your running on. If its a "loose" track, thus you are using rubber tires. I would stay with the long shocks. If your are able to run Foam tires (Hard Packed Tracked), i would go with TC shocks with short shock towers.
Take a look at this: http://www.speedysracingparts.com/
. They have Conversion kits and other cool parts for Dirt Oval.
. Awesome Dirt Oval bodys and products. Dan is a standup guy! Delt with him on multiple occasions.
Hope this helps!