Gotta tear engine apart, things to consider for performance and mileage.
 

I have to replace the rear head gasket on my 94 Voyager 3.0 V6. Being who I am, I am in search of more performance, and better economy. I have a short ram intake already which picked up 2mpg on average. The 3.0s run very rich from the factory and have to get a significant amount of extra air before the ecu will add any more fuel.

So far I am planning to do some port work on the heads along with a valve job and seals, port and install my big throttle body, and install my ported non-egr intake plenum while it's apart.
It will be needing new exhaust soon as well so I plan on bumping that to 2.5", with better flowing cat and muffler.

Any other ideas, or insight?

I have three tips:

1. ECU reflash: a lot of people reflash or change their ECU to get rid of government regulations to improve horsepower or fuel economy or both. It usually takes a few years for aftermarket companies to create better air fuel mixtures than factory. This is very common for motorcycles and sports cars, but I'm not sure if you can buy anything for the Voyager.

2. Hot air intake: I heard that if you heat up air in your intake it can increase your mileage, but I don't understand how this would work or why. I know that cold air intake gets you better horsepower but maybe fuel economy suffers, so maybe hot air has the reverse effect.

3. Manual transmission: I know that some Voyagers came with a manual transmission option, but I'm not sure what engine they were mated to. Also, they are very rare, so finding one could take a long time. If you have the right tools, changing a transmission out is not as bad as most people think. (Never changed transmissions before, but watched other people do it).

1. Not much for aftermarket unless I go stand alone (Megasquirt).

2. I already have a Short Ram Intake, which could be considered WAI, seeings it is located in the engine compartment.

3. I have swapped a relative vehicle to manual, but being a daily, I would rather keep with the auto.

I currently have been averaging over 25mpg, so I'm definitely not complaining about my mileage.

Heads are getting ported and refreshed. Installing a ported/polished intake plenum. Installing a ported 52mm TB. Will also be doing larger exhaust soon.

So how did this project end up?

Been driving it for months now. Did mild porting on the heads and shaved them. Installed a ported non-egr plenum. Installed a 52mm TB. The engine runs great, with a nice bump in power, doesn't seem to have bothered mileage.

I'm now researching putting a 3.8L Mivec from an 07 Eclipse GT into it for even more power, which I have sitting in my garage.