[1970GTOs]

To start with HELLO to all members im new here and I hope to learn and help as much as I can.
Next I bought a set of Pontiac heads for $20.00 dollars never touched with casting number 15 and a number of AO98 what im trying to find out is what year these heads are from and what H.P. they can produce according to www.wallaceracing.com and what block to use 455 or 400 when using today's gas what I want to do is built a motor like I had in my 1970 GTO from High School for when I find the body I want I will be ready or that much ahead. Thanks! 1970GTOs

[Will]

Casting dates decode like this:

The 'A' is the month the part was produced. Since 'A' is the first letter in the alphabet that means the heads were cast in January. 'B' would've been February, and so on.

The next two numbers, '09' in this case are the day of the month. So, January 9th.

The last number is the year. Could be '58, '68, or '78 but #15 heads were only used in '68 and '70, so those must be for the '68 model year.

If you go to the Wallace Racing site, look for the "Pontiac Head Search" link on the front page. When you click that link you can enter just the head code (15) and it will return all the years and applications for that particular code.

To save you the trouble, those are small-valve heads that were used on 400s with 2bbl carbs in '68. They have very nice chamber sizes for use with pump gas on a 400 engine today, they will make right about 9-9.5:1 compression on a .030" over 400. Their potential is hampered by the small valves and pressed-in rocker studs though. If you have the pressed studs converted to screw-ins and have the large 2.11"/1.77" valves installed with some port work to enlarge the ports to match they will work as good as any other D-port head out there for a street or street/strip type engine.

You can use them on any size Pontiac engine, just get pistons with dishes on the larger motors to set the compression ratio where you want it.

How much HP the engine will make is a function of how you build the engine - the overall combination of parts - and what work you have done to those heads. The stock horsepower ratings for engines with those heads are pretty meaningless.

[BILTIT]

http://www.wallaceracing.com/head.htm

[1970GTOs]

Thanks for the info.