What's a good engine conversion for fuel efficiency?

I have an '87 S-10 Blazer with the 2.8. It's my daily driver, and I'm looking into conversions. The speed freak in me wants to drop a LT1 or another 350. But I'm also looking at the Vortec 4.3s. Could I get a 350 to get decent MPG, close to the 4.3? Looking for 20MPG +/- 2. Thanks.

Call me crazy for saying this, but I have a '95 model with a 4.3 and I'm getting the same gas mileage most fullsize v8's are getting. I believe if you put a big motor in your truck you should get decent mileage, mainly because it's not as stressful on the motor. That's just my opinion.

Nick

Absolutly true and then again not. My '84 4x4 ecab had a 2.0 with 183k on it. 12mpg tops and 0 to 60 in 24 sec. (yes I tried). A small block can get you 20 mpg easy. The problem is 1st: when you're building it you'll slowly decide it's just as easy to start squeezing in a little more cash for a little more power. 2nd: When it's done you'll realize that you like the power more than the economy and the local filler-up will know you by your first name as your right foot gets heavier. More power or better mileage, you can get both from the same engine, it's up to you which you prefer. I say by all means, GO SMALL BLOCK. Screw the 4's & 6's!
-N8