Heads
 

Ok i need some info guys right now i have a 455 with 4x 1H heads on it and i have a chance to get a set of 74 350 GTO # 46 494346 Screw 2.11 1.66 89 will this give me better performance then the stock 455 4x 1H heads ???

Replacing your 114cc heads with a pair of 89cc heads will give better performance for sure..........grab´em.

You will need to watch the rest of your build to make sure the comp ratio does not go too high if you want to run pump gas.

I have a set of these heads as well...but I thought the valves were 1.96\1.66. With the small chambers, I always thought they might be a good head to port and use on my 406.
Chris

Definitely double check that valve size as I too thought they were small valves. Still, the chamber size is much more favorable and adding larger valves isn't a problem.

Thanks for the info guys i am going to grab on to them here is a link to a pontiac site with head id and stuff from 1959 to 1981 thats where i got the info on these heads and it shows in 1974 2 sets of #46 heads one set with the bigger valves 2.11 1.66 89 volume and the other set with smaller valves 1.96 1.66 ...98 volume take a look http://www.angelfire.com/on/geebjen/heads.html