Let me tell you something- Before you get up in arms about my comment, realize that I have been a Toyota enthusiast before your balls dropped.
Hell, I even remember when the Supra was put to an end for the U.S. and even being upset by it. I'm 22 now and that would have made me about ohhh,.. 11-12 years old? And you were how old?
Honestly, I could probably tell you more about your MA61 than you'll probably ever care to know. BTW, I hope you changed your valve seals .
Sure, the 5M can make respectable power.. you're making what, around 200hp with your simple turbo kit? Unless you've got something other than an itty-bitty CT26 you're not going to get too far. Of course there are always the Hybrid CT26s, but most have minimal gains without much modification to the housing itself.
Are you really asking me why I think the 5M is just about worthless? Do you really think an obsolete Toyota 5M will ever be on the same level as any J series? The 7M is respectable as well, but still not the same as any J.
Don't get me wrong, I completely respect you and your dad for restoring your MA61, because it's a great looking car.
*edit* FYI, I'm still no expert by any means, but I feel I'm only pointing out the obvious.