gear ratio in a k5

The 700R4 is notorious for part throttle shifts out of OD into Drive.  Approach an incline and give it some fuel and they instantly downshift.  It's the MO of that tranny.  I believe B&M makes a part for it that makes the tranny downshift only after 3/4 throttle or more in OD, something to look into.  Also, the gears are way too high for 33s.  Alot of guys will tell you otherwise, but look at the gears that are coming in vehicles from the factory with 31" tires or smaller.  Most SUVs are in the 3.55 range with a 29" tire which is probably what that blazer came with stock (talking about tire size).  Can the 350 handle those tires with that gear ratio?  Of course, I will not argue that at all.  The issue is where the motor makes its power and where it is at it's cruising speed.  If your traveling down the highway at 65 MPH and your only turning 1300 RPM, then you are geared too high.  You most likely need to be around 1800 rpm to be in the "sweet spot" of the motor.  Step up to a minimum of 3.73s here, I would go 4.10s if it were me and I planned on stating with the 33" rubber.  If you decide to step up to 35s, then you should go with 4.56s to 4.88s.  And remember, adding power enhancements like K&N air filters and intakes and what not will help you make more power, but if you're not making the power in the right RPM compared to vehicle speed, you're throwing good money down the drain.  It's just like matching a performance camshaft with the proper torque converter.  If you're off by a couple hundred RPM, it can make a 400 HP motor seem like a dog off the line.  Gears are the real fix here, no doubt about it.  They go hand in hand.....bigger tires neccessitate lower gears.....period.