Access holes for bell housing bolts

I will go on and answer your question, @gm1236. If I just "had to have" access like you are asking about, what "I" would do would be to form another firewall/transmission tunnel transition right there in the very front of the transmission tunnel. I would cut the original section out a little smaller than what I made, so that there'd be about 1" or so overlap all the way around. Then place the new panel over the opening. Drill holes through both panels all the way around at about 4"-5" increments. Next, put some clip on nuts like these in each hole in the original panel.

https://www.mscdirect.com/product/details/51240455

Put some sealer all the way around the panel opening and screw the new panel on. But I will echo the sentiment of others. I've never had trouble getting to those top bolts either. That said, there's no way to know what you have. You may have something different than what any of us has seen. Maybe your engine is further back somehow. At any rate, if I just had to do it, that's what I would do. Make a large removable panel, instead of two smaller ones.