the 3550's are 'stronger' than a stock t5, but the 3550 is only rated at 350 ft lbs not 525. the 3550's retail at 1400 but you can find them for cheaper here
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33733&item=2448606265
also, the t5's usually have a taller 2.97 first...