Seriously?
The syclone/Typhoon was a good 4 seconds quicker in the quarter and 0-60 times were about half of what your '94 Blazer were. Apples and oranges.
In my opinion the 4.3 was a true compromise engine born out of GM's accounting department. True, after 20 years of constant tweaking, they finally ended up with an engine that ran smooth, made acceptable power, and got reasonable MPG. It's still a light truck motor though and there are about 100 better choices for a Gbody. If you are going through the trouble of an engine swap, I see no reason not to go with a 350 over a 4.3. The cost would be almost identical if not cheaper for the 350.
Regarding your original post's question about 5-speeds; ssn969's post pretty well covers most of the bases. I'd like to make one correction though. He mentions the '93 S10 being a WC with Ford front case pattern. While it
is a WC, the good news is that it has a std GM front case pattern. I have 2 in my shop right now. The input shaft is about 5/8" longer than you need but can be shortened if you know someone with a lathe. Just cut back the splines and trim off the snout. The input shaft can even be removed without disassembling the transmission. Easy modification. Then you need the matching clutch disc which is readily available.
I know that the torque rating makes it look like they aren't very tough but my dad has one behind a supercharged LT1 and it's been fine for a couple years now. Think of the T5 like the Saginaw or the 7.5 rearend -- if you don't blatantly punish them, they'll live a long time.
One note of caution. When adding an overdrive you'll need to consider rear gearing also. There can be too much of a good thing. They need to compliment each other.
+ mine wasn't even that good someone could really smash out w/ the mitsubishi turbos from typhoon/ syclone if they could figure it out
