Starting a new build...

[gearhead2069]

So as I am finishing up getting just a few small parts here and there for getting this thing started, in the interest of keeping the project going I need to start thinking about engine and transmission.

I plan to use the truck as a daily upon completion. My plan is to shoot for a reasonable MPG (because let's be honest... Gas is never going to go down) while having something to play with when I need it. Chevrolet is getting some pretty impressive figures when it comes to their Camaro and Corvette. The Camaro is now pushing around 430hp out of their LS3 (which can be purchased as a crate) and is rated around 16/24mpg. The curb weight of the Camaro comes in around 3860. Apparently the curb weight of the truck was 3175 back in the day. I looked up the weight of the 219 I6 that came with the truck and it weighted in a little over 600 whereas the LS3 comes in a little over 400. Along with the different suspension components I can only imagine the weight is going to remain around the same if not drop just a bit. I realize that aerodynamics are going to come into play here in favor of the Camaro but surely I can get some pretty reasonable figures here. In favor of maximizing my MPG I'd like to go with a 6 speed. I am fighting the idea of going with a manual for two reasons. One- as I want to keep a bench seat in the truck, I'm curious as to how long the throws will be (every stick I have ever driven has been in a car) and I'm afraid longer throws will take all the fun out of it being a daily. Two- as I plan on searching around for some internals to make the diff a little stronger, I still fear a manual being rougher than an auto on the diff. I don't know, feel free to chime in or correct my logic.

So as far as 6 speed autos go, I guess I could go with a 4L80e that was been modified into a 6 speed but I have been seeing a few reviews where this results in a less than perfect tranny that doesn't really have the greatest longevity. This leaves me with a 6L80/90 though I am leaning more towards the 90 as I believe it is probably closer to a true 6 speed tranny than the 80 when reviewing the gearing. I'm thinking the 90 may give me better results.

What do you all think?