Is there a difference between 74LS245 and 74HCT245 ?

I am trying to do the schematic at the bottom of this page: http://www.mikroe.com/esupport/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=151
And I found I have a 74LS245, but I don't have the 74HCT245, can i still make the schematic with a 74LS245?

 

The output high voltage of a high speed Cmos 74HCT245 is 5.0V.
The output high voltage of a TTL 74LS245 is only about 2.7V to 3.5V.
The IC it drives might need a minimum input high voltage of 3.5V, look it up.

 

The 'T" in HCT means TTL compatible.

 

What about differences in speed?

 

It should be okay, the LS part will use more power.

The schematic is kind of fuzzy for me, but it seems to me that the OE pin is floating and that only one of the three output signals has a corresponding input?