When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
There are a bunch of threaded holes on the ends of the heads...some get used for mounting brackets, but most don't. When I look thru them, it looks like I can see head bolts! Anyway, am I supposed to plug these or something?
They are the ones circled in the following picture:
Yes that is a head bolt you see. It is an accessory bracket mounting point for AC if the vehicle is so equipped. If you're not going to use them they'll be fine unplugged.
Another stupid question (and I apologize if I've asked this before here): is there ANY difference between the left and right heads on a 351M? Because I can't find any. I didn't mark which one was which when I took them off, and it doesn't look like it matters which way I put them back on.