Just out of curiosity, any particular reason for going to a V-6 from a V-8? In these trucks dealing with a V-6 is going to be more trouble and more money to get less power.
Ok, to further expand:
When the 305 overheated last october (will describe that later) i contemplated just getting a crate 350. This would have been simpler and truck would most likely be running again by now.
Actually what i
really wanted was a diesel. But i'm not real familiar with the 6.2 vs. gas engines---even though diesel is simpler. But i think a diesel swap would require a lot of parts and pieces which aren't there now. Whereas with an 8 to 6 swap everythings pretty much there. Though some modifications might be required---such as lengthening hoses, drilling etc. But everything is basically there. i felt i didn't have time to research diesel right now. Maybe it will be my next project.
i had actually bought a 4.3 cheap before the 305 expired just to experiment with and because i really like this engine. It sat in the garage for a while. When the 305 gave up, this seemed like the natural choice.
The truck had a 350 before the 305. Both got about average 16 mpg. Both were able to get about 17.56 ish on long highway trips. Being that i use the truck for daily transportation with the ability to do occasional weekend hauling (mostly hardware store or large but not super heavy items) i did not feel 16mpg is acceptable for me.
Now, will 43 less cubes really make a significant difference? Well, it's more than just 43 inches;
Less pistons/cylinders, main bearing, lifters equal less friction.
125 lbs. less weight.
Less rotational weight due to shorter crank, cam.
Less reciprocating weight.
So, i'm betting at least 19mpg which i would be somewhat satisfied with given the size of the truck.
Really, in the long run i feel i will be happier with this engine vs. another 8 even though thinking more about it if i had gone with a crate 350 it would not have been a terrible choice given that i'm pretty busy and short on time these days.
P.S.
The 4.3 makes almost as much HP and the same torque as the LG3 305. Albeit the torque happens 400rpm higher on the 4.3
I'll be interested to see how it works out for you. Based on anecdotal evidence, high teens is usually out of range for these trucks without a diesel, so I hope you get there. I think what will be working against you is that 4.3 will be working harder to move the truck around than a V8 would, which may erode the potential economy advantage unless you're doing a lot of highway driving. Best of luck!
