I have a 79 E250 with a 351W motor in it that I have been living in. I was having problems with the motor and thought I had a blown head gasket and some oil in the fuel problems. It turns out that I did have a blown gasket but most importantly a cracked block. I'd like to swap the motor out with something that could continue as my daily driver.

My concerns are this. The old motor got me a whopping 10-11 mpg. I'd love to get some better fuel mileage. If there would be a way to swap in a 6 cylinder motor without too much extra work that would be great! I don't know what type of transmission is in the van, c4 or c6, (i get them confused all the time) but it has a 3 speed automatic.

I've found some 351W motors for around 500 dollars that I could probably swing in the next few weeks but again if there were a way to put a better fuel economy motor in it without too much extra effort and money I'd love to hear your ideas. I'm just looking for some good sound advice and I'd appreciate it greatly. Thanks!

Loyal

 

> I'd love to get some better fuel mileage.

The vans are like sheds on wheels, they are not aerodynamic, and weigh 5,000 pounds. You will get just about the same as the 6 cyl 2 bbl., it is not worth the conversion headaches. I know, I owned a 1980 300 c.i. automatic. You might be able to eek out more, but, the real limiting factor is the transmission.

If you went to the 300 and 5 speed, you might be able to push 15 mpg highway.

Going Pertronix (yours should be mechanical/vac dist.) on your dist. would gain you a MPG increase and is worth the money.

If you are living in the van though, make sure to keep the ignition off with the Per., as it can wreck it.

 

Just to add my 0.02 he,s right its not worth the headache ,but my 300 was getting 14 mpg .then i switch out for a 460 just mainly for the power,but it was getting 12mpg if i kept my foot out of it lol.