bore out my 260 or use a 280 block?

[GGRIII 7]

I have a 260 with 188K original miles and this winter I am going to rebuild the motor.  My original thought is to keep the E88 head but stick the larger intake valves in it.  Then mate this to either my 260 block that has been bored out (keeping the car matching numbers) or use a 280 block with flat top pistons. 

So I have 2 questions:

1. Has anybody bored out a 260 block, is it the same as boring out a 240 block, how much can I get away with?

2. If I use a 280 block with my E88 head is there anything I should look for, I guess my concern is with oil and water passages.  I know my E88 has a spray bar and wasn't sure about how that would work with the later blocks...

[Diseazd 787]

Use a 280ZX block....bore it .040 over, use P79 flat top pistons, use the modern P79 head or N42 head (not the E88 that you have). If you go P79 head, shave and shim it .080 and install a Isky Stage III Cam. Put your numbers matching engine on a stand in the closet. Now you’ve got a fun engine!

Edited July 22, 2019 by Diseazd