gen 1 sbc and bbc's are more plugged up stock for sure. Longtubes helped a bit with the stock 350's in my previous and current 72 chevs

 

if you're referring to that 3rd Gen Camaro tested on one of those television shows, i remember seeing the owner of the car post somewhere that all the "before" parts/fluid were on their last legs - which would obviously make the new stuff look like it did more to help.

 

Not sure what car it was. Most agree that sythetic will net you a small amount of power. It also keeps thing a bit cooler. I run sythetic in everything just havn't had the money to do this oil or trans yet. Trans kills me at $150+

 

Ever thought about a Gear Vendors Overdirve unit?

 

I am sure it wouldn't be cost effective. I guess it is something to look into.

But the unit, shortened shaft equals lots of money. 1-2 mpg would take a long time to pay for it's self.

 

E-fans, and Synthetics.. will net alot,

If this is a 2500 HD burb, then get a set of the forged aluminum HD wheels and some LRR tires, that will net another good chunk, Headers, and a TB spacer will get another good amount, go with a phenolic spacer to alleviate the heat sinking into the TB as well.

Between all of that you should be looking at some good gains, this is the path that my friends father took and like i said in a Previous Post he gets nearly 20mpg...