MC3459P -- What makes a good substitute?

Some repair services suggest using 74LS37's or even 74LS00's to replace the Motorola MC3459 located at U15 on Bally & Stern CPU boards. This is not a good idea as this violates loading of the IC per manufacturer specifications. Overloading can result in intermittent errors and/or shortened component lifespan. Below is a table listing loading for each output pin of U15 plus a comparison of various IC's that people have used to replace the hard to find MC3459. Green values are areas of valid operating load conditions. Red values are areas of concern. Pay particular attention to output of gate 4 (shown in red) which is required to sink a minimum of 37.6mA. Only four IC's show themselves as being capable of sinking this 37.6mA: MC3459, 7437, 74S37 and 74F37.

	Required Bally High level current loading	Required Bally low level current loading
U15, Gate 1	< 0.080mA	7.4mA
U15, Gate 2	< 0.040mA	5.8mA
U15, Gate 3	0.150mA	7.2mA
U15, Gate 4	< 2.52mA **	37.6mA ***
	Available High level current per pin	Available Low level current per pin
MC3459	18mA maximum	122mA maximum
7400	0.4mA maximum	16mA maximum
74LS00	0.4mA maximum	8mA maximum
74S00 / 74F00	1mA maximum	20mA maximum
74HCT00	4mA maximum	4mA maximum
7437	1.2mA maximum	48mA maximum
74LS37	1.2mA maximum	24mA maximum
74S37	3mA maximum	60mA maximum
74F37	15mA maximum	64mA maximum

Notes:
Current values supplied by actual manufacturer datasheets.
Operating voltages based on manufacturer specified values.
Low level voltage based on [VSS + 0.8] or 0.8 volts (maximum).
High level voltage based on [VSS + 2.0] or 2.0 volts (minimum).
** Most IOH of gate 4 is provided by R137 (provides up to 20mA source current).
*** Most IOL of gate 4 is created by R137 (adds 28mA load current).

Conclusion:
Although some repair technicians suggest using a 74LS37 or one of the other 'red' components listed above is valid, this may result in intermittent operation or shortened lifespan. For best results - use only these parts as valid replacements: MC3459, 7437, 74S37 and 74F37.
And remember - "it always works for me" is not justification for a part that is an invalid substitute!