Engine rebuild (OE vs Aftermarket)

[aklackner]

All my [un-credentialed] .02

Direct answer
If pulling it apart and going for 220whp, buy high quality, purpose built components and build the bottom end to support that if you want to keep this long term. At a minimum I don't think you want to trust OEM rings to take the pressures and RPM required to generate the amount of required force dependably for long.

Questions
Are you sure the BC cams are the 3 or the 3+, that might affect the build. Any reason for these over other options? I'd really recommend taking care with cam selection and make sure it's going to fit well with goals and the build. I know how it goes but general wisdom is to design the build around goals (not just hp but where you want the power band) this will inform displacement then you can find a cam to fit that

Ramblings
For an NA B18C5, 220 (assuming this is WHP) is a significant target.
ITRs with minor bolt-ons are frequently in the 170whp range, mild cams commonly land ~180-190, aggressive\high lift cams +skilled tuning 200+.
Getting to 220 whp would be an increase of peak output by 30% over an already highly tuned OEM motor. Building NA to 220 in a reliable (OEM sense of the word) will be expensive and may be hard to achieve with a lower lift (long duration cam, if this is the original bc3 cams).

No matter how you get there adding 50whp in an originally 1.8L motor means more heat, more pressure. Both of these are leading contributors to pre-detonation. Cast pistons don't handle extreme forces of pre-detonation (well). You'll be running some form of aftermarket engine management, plus modifications to the motor. This means you can't really rely on meaningful knock detection, or generally much in the form of safety systems, at least at the sophistication that OEMs implemented (even in the era). Implementation\restoration of OEM level safety systems is typically prohibitively expensive.

While there's probably umteen examples\stories of high power builds with OEM components keep in mind you've increased the risk of pre-detonation (knock). Consider very carefully your tolerance level with risk that your specific set of castings are up to the abuse to deliver trouble-free and long term.