Don't get me wrong, I have no issues with people modifying their cars, after all it's their car to do what they like. But @Pushrod Scott mentioned that his budget was limited (probably not as limited as mine), and he didn't want his car to sit around accumulating rust. So my comments were about doing it at a budget and a reasonable time frame. IMHO, best option would be a good running flat head for that car. Finding one might take upto 12 months, but once you find one, its a weekend swap over. What would a good running flathead cost, $1k?
What would it cost to do the SBC & TH350 swap? $2k? $4k? And if you are doing it yourself with limited experience, how long would it take?