I was looking around a lot for heads to put on my truck and found that the used engine I bought to rebuild came with 193 swirl port heads. Then it got me thinking what heads were on my truck since I bought my truck from an awful backyard mechnic that said he doesn't know how the engine was, he just dropped it in since the original 350 burnt 6 quarts of oil in driving 2 hours So he called the other engine good enough without even knowing anything about it. So I was extra curious since my left hand head on my truck is painted blue while the other side is rusty like the block.... so I checked the blue one since its easier to take the valve cover off and it's a 191 head. Just wondering what the benefits to the 191s are or cons over regular 193 heads? I heard the 191s are just hardened 193s? It makes me wonder if the rusty right hand head is another 191 or not..but it runs better since I timed it correctly now and put AC Delco plugs in it...before it was badly out of time and i don't remember how many spark plugs didn't work....

I've researched the 191 heads on the web already a little but didn't really come away with anything other than they're like 193 heads, after that the forums erupt in how bad the 193 heads are and I don't find my answer Lol I have a 4x4 K1500 so the swirl ports are OK...and cheap with good fuel economy! Just wondering if anyone had specs on them.


Thanks!
Jordan

 

AFAIK the 191's and 193's are nearly identical /direct replacements.

 

so they're close. but why would GM use a new casting number if they didn't make any changes?