Advice- bi-amp using integrated amp


I have bought an older version of the same integrated amp (only has pre-out terminals, same power rating, similar spec’s.) for a power amp. How should I configure it? :

1. ‘Power amp’: Connect Amp1 ('pre') pre-outs to a line-level input on Amp2 ('power'), bi-wiring from Amp2?
2. 'Bi-amp' : Amp1 driving the highs on both speakers and Amp2 the lows to deliver cleaner power? Would this introduce delays between the frequencies?

Any thoughts/ comments appreciated,
Option number 1, as you've presented it, won't work, at least if your goal is to bi-amp. You can certainly bi-wire this way, but it's not bi-amping. It would just be a regular pre amp/power amp set-up, with the speakers being bi-wired. In this set-up, the power amp section of amp 1 wouldn't be doing anything. Both speakers are being powered by amp 2 alone. To bi-amp, you would have to connect the speakers to both amp 1 and amp 2.
AFA I understand what you're saying, you need a connection as per 1 & powering as per "2".
As to delays -- you probably will have phase irregularities between low & high. You probably won't notice these
Thank you both for the advice!

I hooked up using the power amp option with a noticeable improvement in sound, to the surprise of a local hi-fi distributor who said there would be no difference in just using the power amp section of a second amp and the pre of another = the same as an integrated amp! ... trust your instincts and be willing to experiment, I say! I'll try to bi-amp shortly, despite being told by the same person that it's NOT possible!