Subframe connectors needed or not?

How much hp/torque can a 67 A-body take before really needing subframe connectors? I don't plan to hit the drag strip a lot, but I think it only takes one shot to bend it if it hooks hard enough.
If recommended... What aftermarket BOLT in type do you guys recommend? I know weld in ones are better, and I may do a bolt/weld in combo. I really don't want to pull the seats and carpet just yet.

**** a stock slant 6 car can and will benefit from frame connectors..

i followed this in the past and they worked out well. https://web.archive.org/web/20080216222924/http://www.bigblockdart.com/techpages/connectors.shtml