I have a 200 cu. in. straight 6 in my 1966 Ranchero. I'm looking for something, how should I put it.....bigger. Is there anything I can put in without getting a new transmission?

 

You will have a tough time finding the info as to whether your tranny will bolt to a v8. I doubt it.

This site talks about lots of 6 cylinder changes.

http://www.inlinepages.com/drivetrain/history.html

If it was my fine '66 and was worth the fixing, I'd go with a mild 302 and an AOD.

A friend did this to his '65 six Mustang with great results. Not cheap, lots of swap to do it. Must set it up correctly. All this has been done, you just need to research before you dive in.

You may need a new front end under this thing too. Do you have 5 lug wheels or 4 lug? Do you have a dropout carrier 8" diff or an integral unit?

There are ways to warm up the six, including, if it will fit, a 250 version.

While you have the motor out, it's a good time to reweld all the laminated spotwelded stock spring towers, subframe rails etc.