[6pack] HVDA and antifreeze - two questions

[richard olson]

Antifreeze -
I put "Prestone" in 1997 (I got my 1972 TR6 in 1996).
In 2000 I fixed my heater and put new antifreeze too.
Now its 2008!  Is this a good time to put new antifreeze in?
Is "Peak" use?  Went do I need to put new antifreeze in?
2 years? 5 years?..... each year?
 
Gear oil -
I got my HVDA in 2003. I used "Pennzoil"(?) for my gear oil, GL-4,
75W, no synthetic (I can't remember?).
When do I change my Toyota gear oil?
Should I use a synthetic (Redline MTL)?
 
Rick Olson, '72 TR6