Tell me why not?

Much depends on how many $$$ you have to spend, best bang for the buck & how much disassembly you are willing to do. Changing heads ain't simple if 'you know nothing about engines'.
If you want to feel a noticeable difference & keep costs down, I would use your Edel intake & carb....but change the cam. The cam I would get that will give you street manners is the Isky 264 Mega, #390164. Have your factory lifters re-faced, which guarantees the cam runs with good quality lifters & not today's crapola lifters. I think your factory valve springs might work with this cam, others might know for sure. If not, springs can be replaced without removing the heads.
It makes little sense to me to spend big $$$ on a small engine like a 318 as it is cubic inches limited...& low compression, both performance killers.