All Small Six 1966 170 vs 200

[66bronco]

A friend has a 1966 Bronco which only came with a 170. But after I started to work on his truck the prior owner(s) changed a handful things on it. But what I noticed right away the motor as 5 freeze plugs. All my 170’s only had 3 freeze plugs.

First is that a dead giveaway it’s definitely a 200?

Secondly are there really any differences besides the freeze plugs that would not make 100% interchangeable?

He wants to keep this bronco as close to stock as possible. Or so should I tell him to look for a true 170 or suggest keep the 200 even tho it’s not correct for his year bronco?

Thanks in advance Jeff

 

[DON]

Yes, dead giveaway, it is a 200
The two engines are similar but the 200 has improvements. Depending on the 200 and the existing transmission, the swap wouldn’t be bad. I would suggest if he wants it original, to find a correct year engine and tranny if needed. Most people will not know the difference, only people looking for original will know. Also what level of original is he trying to achieve and the $$ to spend getting there