Hey guys, thanks for the help. This is my first post. I apologize if this has been covered already, but I can't seem to find it.

Every time I order engine parts I'm asked if my engine model is a B or a K. What's the difference, and how can I tell which one is installed?

 

Probably engine code, that's the fourth digit of the VIN.
73-79 "B" is the 300 cu in 1 bbl. 6 cylinder.
78-79 "K" is the heavy duty 300 cu in 1 bbl 6 cylinder.
As far as I know, all F100-350's with the 6 cylinder engines were "B".
Welcome to FTE, lots of good, knowledgeable people here.

 

That's odd; I've never heard that before. I have a '79 with a straight six and I have never been asked that during all the years I've bought parts for it.

Sometimes parts are listed in the way you've described according to the letter that represented the engine in the VIN. In fact, 'B' happens to represent a 300. I haven't seen 'K' before (doesn't mean it doesn't exist though). It would make sense for some engine parts to be differentiated between the 300 and the 240, but the 240 was represented by the letter 'A', and 240's weren't available in '79 (assuming you're asking about the truck in your profile).

 

^^^ As usual, Mike has the in-depth information.

 

DANG IT!!!! fmc beat me again!

EDIT: I must be losin' it. I thought fmc beat me

 

That's what I was figuring, Mike. I've done some research, and it seemed the only thing it could mean. Then stupid me upon replying to your post went and looked at the old promotional brochure I got with my shop manual disc from MACS and it shows the "k" 300 as an option on the F-350. My bad, I read through it but missed it because it's a scanned copy and I don't guess they wanted to take the binding off, so the heading is missing. Autozone says they were installed in 18% of F-150s, and I think another site told me 10%. Nothing would surprise me. My sister-in-law actually has a Cobra II that was special ordered with a six cylinder in it. She swears she has the paperwork and her dad bought it from the original owner and restored it for her.


Thanks to both of you for the info. Now to get back to repairing my rear main.