[grdn24]

going to rebuild a 70 455 for my 69 gto but just wondering if the #15 heads i have are worth keeping or to look for some other ones.i hate to admit this but im just startin to get to know the pontiac engines as i have always had chevys before.

[grdn24]

going to rebuild a 70 455 for my 69 gto but just wondering if the #15 heads i have are worth keeping or to look for some other ones.i hate to admit this but im just startin to get to know the pontiac engines as i have always had chevys before.

[RicksGTO]

The #15 heads are good heads for a pump gas 455 engine. They have 87cc chambers just like the #64 heads that came on the '70 455's in GTO's, so your compression with a slightly dished piston and zero deck should be between 9.5 to 1 and 10 to 1. The drawback to the #15's is the valve sizes of 1.96/1.66 and the pressed in studs. You will probably want to have them machined for the 2.11/1.77 valves for better flow and you definately should have the rocker studs changed to screw in studs. Most any Pontiac D-ports from the late 60's and early 70's seem to flow about the same, as long as you have the bigger valves. Good luck on your engine and if you decide not to use those heads, let me know and I'll make you an offer on them for my 428.

[Bud Lyons]

Like Rick said the 15's have some draw backs. Before you have all the machine work done to the 15's. Check and see if you can buy a set of 6x's or 5C's already done for less then what it would take to get the 15's done.



My Rig's a little old, but that don't mean she's slow.

[John Bailey (GTOKID)]

get the heads drilled and taped for screw in studs and rebuilt they are fine for a nice driver to a 12 sec car.

[grdn24]

thanks for the info guuys that was just what i was lookin for ,like the 12 sec part if ya know what i mean what would the cost be usually to machine for the bigger valves and screw in studs?