Yeah. The thread-starter's in north Texas, I believe. So yes, stick with the 10W-30, or even an SN-rated 15W-40 in the summer wouldn't be bad, that is if the oil pressure dips too low in summer weather. Those 4.3L engines will run nearly forever if properly maintained.Keep on keeping on!! Stick with your Maxlife 10W30. My gf's dad had an S10 Blazer of that same vintage. He either had near 300,000 or a little over 300,000 on his. He only sold it because he needed a bigger "truck" to haul around all his maintenance equipment and items for his rental properties. He is a Castrol guy and always used Syntec 10W30 in it.
GM lopped 2 cyliners off the 350 block, coming up with the early 4.3L engine (not today's EcoTec 4.3L). Turned out to be a great thing for them and us.