55.2-59 Engine rebuild. Question on heads

[Phungki]

It’s not the original engine from that car. Looked up the casting number and confirmed it was a 350.

[1project2many]

Originally Posted by Phungki

It’s not the original engine from that car. Looked up the casting number and confirmed it was a 350.

Well that's good news. But youch! 305 heads on a 350 can cause pretty severe detonation issues. It raises compression significantly and the sharp edges of the chambers can get hot enough to be a trigger point.

Modern head designs for street vehicles don't require angled plugs to get best flow. Go with straight.

Be warned that if you get a Vortec head the centerline of the exhaust ports is not in line with the centerline of the bolt holes. You may have to "walk" the holes closer to the top of the header.

[Phungki]

Originally Posted by 1project2many

Well that's good news. But youch! 305 heads on a 350 can cause pretty severe detonation issues. It raises compression significantly and the sharp edges of the chambers can get hot enough to be a trigger point.

Modern head designs for street vehicles don't require angled plugs to get best flow. Go with straight.

Be warned that if you get a Vortec head the centerline of the exhaust ports is not in line with the centerline of the bolt holes. You may have to "walk" the holes closer to the top of the header.

From what I have read there really isn’t a significant difference in performance between straight or angled. I was just wondering about header fitment. If either one gave me more options.
I’ve read vortec is a better head but I believe I would also have to change my intake if I got those. I don’t want to do that. The one it has is fine. I’m not trying to squeeze every horse out of this thing anyway. But to get these heads redone is only about $175 away from a new set at summit so I figured I’d go that route
And end up better off
Thank you for the responses. I appreciate the input from ppl who have “been there done that”