From an economy standpoint, I depends what the engine is replacing. Small block out, small block in would be pretty simple. If you switch to big block, the cost will add up quick.
true, but it also depends on what is done to the big block.
a stroked 318, bored and all the parts and such, especially a grand in the heads alone, all adds up too. Where as if you're taking a stockish 383 with maybe a small cam and intake upgrade, but with the stock heads and making the same power, then that grand from the heads, goes towards the transmission adapter plate and cooling. it becomes mute.