I want to replace the 4 banger with a V-6 capable of AC and more HP. Suggestions on a replacement motor please?

 

How do you have a 4 cyl in it? This would mean you'll more than likely have a 4 cyl transmission.

You could always look for a v-6 engine/tranny combo out of a ford ranger I suppose. Either way, you've got a lot of work ahead of you.

Another thing to consider is a 300 i6 engine/tranny combo. You'd be able to use a large six crossmember stock though you would need to get a pair of crossmember mount hangers.

 

No Econoline of any year came with a 4 cylinder engine. 1961 Econoline available with the 144 or 170 OHV I-6.

 

Your 1961 Econilne probably came with a 144 straight six. Many were replaced over time with a 170 or a 200. If you do not have a 200, that is what I recommend. It is an easy bolt-in replacement for the 144 and 170.

The V6 is a wide engine, so you will have problems squeezing it in between the seats. A well-built 200 should be cheaper and more powerful than any V6.

 

A cousin of the 170 straight six is the legendary 300 Cu in 6 or 4.9 ltr in EFI form will bolt in your van easily. The EFI version in my van has 280 ft lbs torque which is more than most v8.

 

The 300 will need the large 6 cross member and support hangers welded to the frame. Also another transmission, driveshaft, and you'll probably need a 9" rear end to handle the torque.