Hi fbracer, I've emailed with you about your car (I'm Chad from Ontario). My Fejer has a Twin side draft carb'd 2T engine, 3tcgarage.com is great for all kind of old toyota engine info/know how. There can find links to service manuals, and part numbers. Unless your looking to get caught up in an arms race for more power which will be costly and time consuming, use the current motor, get out and have some fun.
P.S. If I had the money and time I would have more power though....