5 Is only half true. Any b series header will bolt to the b20 head, but not all b series intake manifolds will fit. Any b series non vtec intake manifold will bolt up, b18c1 will not fit, b18c5/b16/b17 will fit with modification.
I guess my main concern was retaining my ac. I want to go non-vtec b20 so I can basically have a stock-ish, reliable engine with low low miles. (my B18A is at almost 200k miles) That is kickass!
Mounting is the same for the compressor, though? I realize that i have to transfer over my crankshaft pulley to the B20, so it wont rub or screw anything up. But will that affect the space between the ac fan and the compressor? I’ve read in some posts that the block of the b20 and b18 are very similar in outer dimensions, its only the inner measurements that differ. If this is indeed true, then there wouldnt be an issue.
Either way, thank you both for the information! B20 here i come…