Ok your confusing late model heads with vortecs. The vortec intake bolts ALL go STRAIGHT down. and yes I believe there's only 8. The ribbed valve cover and two odd angle center bolts are 86-90whatever heads. 305-350 same look.

 

Oh... didn't know Vortecs had different patterns, aren't all late models vortec? (learn something new every day). Ya, i had only experianced a 1990 set once (2 center bolts straight up with the 2 on each end angled, total of 6 on each head). All my other builds were early style where every bolt had the same angle, but still 6 on each side.

 

No, Vortecs were made for a few years in the early 90s.

 

Anybody here know what those 1990 heads are? I was under the impression they were vortecs. Summit even lists them as vortec when ordering an intake, due to the pattern with the 2 center bolts different.

 

Ahhhh Haaaa... TBI heads!

 

Actual vortecs are only 4 bolt per side!