SRAM output voltage with 74HC chips
Presumably the SRAM is using two N channel transistors for driving the output pins.
link

This provides more drive current than a P channel FET of the same size with the small disadvantage of dropping 1x the threshold voltage. For TTL this doesn't matter since TTL only requires Vh to be above 2 volts or so. This is a problem for CMOS inputs though which expect Vh to be higher.
There's a few possible solutions:
You could use 74HCT rather than 74HC chips. These have TTL compatible inputs that treat everything above 2V as logic high. Only chips that use the data line values as input must be HCT series since their outputs are CMOS compatible. Everything else can be normal 74HC series.
You could add pull up resistors to the data lines. 1K resistors are supposed to work reasonably well though this depends on fan out and operating frequency.

If you're really lazy, considering your circuit is somewhat stable already, just drop the logic supply voltage by half a volt with a diode. The 74HC series logic works down to 2V so 4.5V is not a problem. You don't have to do this for all the logic, just the chips that directly interface with the SRAM. Those ones will now have a lower threshold for Vih and output 4.5V as their Voh which everything else directly powered by the 5V rail will accept without problems. Half a volt will probably get you to stability and this saves having to add the resistors at least during prototyping. Just replace the jumper wire powering the octal flip flop with a diode.