1962 Pontiac SD 421 # 127 heads

[vortecpro]

Anyone know what these heads flow in stock trim 2.020/1.760 valves? Thanks

[mag2555]

Test results use to be on line for those and other stock Pontiac heads, I will try and find it for you, but if I can't I have the info at home somewhere and will just have to dig it out.
Off the top of my head I want to say the Intake side peaked at 220 cfm @ 28" and I think the Exh side followed along pretty good for a overall 72% ratio.

[midnightbluS10]

Wallaceracing.com has some stuff but I didn't see this head.

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

[amc fan]

The 1st SD 421's used 389 heads and put larger valves in them. I am guessing numbers 543797 for 1963 casting,and 538177 for 61-62. :Are you sure the number is 127? In 63 they came out with 9771980 2.02/1.76 (tulip) and they added 15% more port volume. In the April 1991 issue of Pontiac magazine page 38 has the flow @12"Hg. intakes".1-63 cfm ,.2-119 cfm,.3-147 cfm,,.4-169 cfm,.5-178 cfm ,.6-185 cfm, .7-188 c.f.m they flowed all the ports and they were within 5-6 cfm....exhausts ports flowed .1-47 cfm,.2-77 cfm,.3-102 cfm ,.4-120 cfm,.5-132 cfm,.6-138-cfm,.7-140 cfm. Flowed at Jerry Goodale's Specialized machine service, Riverside Ca. with the help of Tony Sizemore aka "Headbytes".

[midnightbluS10]

According to this Hotrod article, 980s avg around 210 cfm and 127s avg around 230 with the bigger valves. Who knows how accurate that is, but there it is for reference.

https://www.hotrod.com/articles/pontiac ... etrospect/

[tenxal]

The 1st SD 421's used 389 heads and put larger valves in them. I am guessing numbers 543797 for 1963 casting,and 538177 for 61-62. :Are you sure the number is 127?

There were two heads that came on the '62 421 S.D. engines:

-The early 540306 heads use a 1.92" intake/1.66" exhaust valve.
-The later 544127 heads use a 2.02 intake/1.76 exhaust valve.

Both heads are correct for the '62 421/405 S.D. engine.

[vortecpro]

Thanks guys for the information.

[mag2555]

According to my notes the 62 127 casting and the 980 casting are the same on the Intake side ,the Exh side of the 980 differe's greatly from the 127 heads.

I still can not find my flow sheets , so sorry about that!

The 405 hp rating was pretty on the money and since the Cams used in the 62 SD motors had .445" lift you would be look about 200 cfm of Intake flow by my best guess.

I also know that the 980 castings have been reworked to 270 cfm with there 2.02" valve size.

Note also that those flow numbers on the Wallace racing site where not taken at 28" or even 25" and the bench they where done on was producing numbers 8 to 10% high!

[vortecpro]

According to my notes the 62 127 casting and the 980 casting are the same on the Intake side ,the Exh side of the 980 differe's greatly from the 127 heads.

I still can not find my flow sheets , so sorry about that!

The 405 hp rating was pretty on the money and since the Cams used in the 62 SD motors had .445" lift you would be look about 200 cfm of Intake flow by my best guess.

I also know that the 980 castings have been reworked to 270 cfm with there 2.02" valve size.

Note also that those flow numbers on the Wallace racing site where not taken at 28" or even 25" and the bench they where done on was producing numbers 8 to 10% high!

What could you see a 127 casting producing for flow in stock eliminator trim?

[tenxal]

What could you see a 127 casting producing for flow in stock eliminator trim?

The 385 H.P. rating isn't a gift but it's not horrible. Also, it's nice that the light weight pieces aren't mandated. Finally, 'Manual Trans Only' is not noted. At 3,828 in 'D' and 4,020 in 'E' it would be a cool bruiser.

[vortecpro]

What could you see a 127 casting producing for flow in stock eliminator trim?

The 385 H.P. rating isn't a gift but it's not horrible. Also, it's nice that the light weight pieces aren't mandated. Finally, 'Manual Trans Only' is not noted. At 3,828 in 'D' and 4,020 in 'E' it would be a cool bruiser.

Do you think theres any way that can go 10.30s in D/SA? Or 10.50s in E/SA?

[tjs44]

290 CFM is pretty much the max im told with a 2.05 valve.A good guy to talk to is Ric Johnson in Creete ILL.Custom automotive.Nunzi Romano has got 300 out of a set of 908s buy said he would not push it over 290 again.Rics number is 7086720101.The 980s on my car are 260s that Indy did years ago and retain the 2.02 valve.Tom

[tenxal]

Do you think theres any way that can go 10.30s in D/SA? Or 10.50s in E/SA?

Given the power it will likely make, I don't see how.

[vortecpro]

Do you think theres any way that can go 10.30s in D/SA? Or 10.50s in E/SA?

Given the power it will likely make, I don't see how.

I don't see it myself-but we will see.

[vortecpro]

290 CFM is pretty much the max im told with a 2.05 valve.A good guy to talk to is Ric Johnson in Creete ILL.Custom automotive.Nunzi Romano has got 300 out of a set of 908s buy said he would not push it over 290 again.Rics number is 7086720101.The 980s on my car are 260s that Indy did years ago and retain the 2.02 valve.Tom

I talked to Ric, great guy! Thanks