[Lefty]

just aquired a 66 mustang recently. my question is, did they only make one six cylinder motor for that year?

[bradsalex]

off the top of my head yes. I have a '67 with the 200 straight six. I'm pretty sure that's the only one they came with.

some research might bring something else up though.

EDIT: According to the Utah Car Club, yes there were only the 200 cid 6 cyl engines.

[Veronica]

Hello. The 170cid six cylinder was phased out in the 65 model year, and the 250 cid six cylinder wasn't used until the 69 model year. The 300 cid six cylinder won't fit in a mustang, so, if your car has the original motor in it, it is a 200 cid six cylinder. That doesn't mean that, somewhere along the line in the last nearly half a century, someone couldn't have put the wrong motor in your car, though. Over on the passenger side of the block there will be a casting number which will tell you what it is that's in the car right now.

[calebm65wr]

yup... it's probably going to be the 200. like was already said, if it's the original engine, it's the 200. now 65s did have the 170 AND 200 but as far as i'm concerned, the 66 only had a 200.