When I decided to upgrade from a GT61, I was interested in both the TE45A & the GT61, so I posted it on here & learned alot about both turbos. Some of what I learned was that both turbo's pull hard up to 25 lbs of boost, but the 67 pretty much is maxed out at that point & the 45a keeps on making power up to 30 lbs of boost or more!! The 45a is also a big shaft turbo where as the gt67 is a small shaft turbo. The 45a is a little more expensive than the 67.
They're both great turbos, it just really depends on what you're goals are. If you're going to stay under 25 lbs of boost, then the 67 has to be strongly considered, but if you ever plan on going over 25lbs, then the 45a is the only way to go. I went w/ the 45a & a 9x11 3400 stall and drive mine everywhere....no downsides to street driving, except had to buy some M/T drag radials to keep from smoking the tires off of it!!!
The Darkside
ps:If you do a search on this subject,you'll find lots of great information!!