PY Online Forums - Bringing the Pontiac Hobby Together

PY Online Forums - Bringing the Pontiac Hobby Together (https://forums.maxperformanceinc.com/forums/index.php)
-   Pontiac - Street (https://forums.maxperformanceinc.com/forums/forumdisplay.php?f=418)
-   -   67 XX with 061 Heads (https://forums.maxperformanceinc.com/forums/showthread.php?t=875406)

ponchjoe 08-10-2024 08:40 AM

67 XX with 061 Heads
 
Hey all

I am looking at picking up a complete XX 400 with 061 heads on it complete with pulleys, brackets and aluminum intake. I’ve read good things about the heads and bad, what’s the thoughts on them if I’m just building a street only engine?

Thanks

steve25 08-10-2024 09:44 AM

For street use with no more than 9 to 1 they will work fine.
They flow as well as any other big valve D port head but they do not have screw in rocker arm studs if I recall right so running valve lifts of over .450” without pinning the studs might be iffy.

They may not have all 6 exh bolt holes drilled either which you would need done to run headers.

ponchjoe 08-10-2024 12:22 PM

I thought these heads might be worth something but I’m not sure. I’ve read detonation issue and also with a little porting they flow great. I see they are a half year and early open chamber but the chamber only lasted for this head, correct?

PunchT37 08-10-2024 12:55 PM

Quote:

Originally Posted by ponchjoe (Post 6519692)
I thought these heads might be worth something but I’m not sure. I’ve read detonation issue and also with a little porting they flow great. I see they are a half year and early open chamber but the chamber only lasted for this head, correct?

Yep. Used to have a set of those. Oddball head/chamber. In `68 they had their open chamber figured out.

geeteeohguy 08-10-2024 01:03 PM

My first car in the '70's was a '66 GTO with a '67 Catalina engine from the junkyard with the 061 heads on it. It ran like a scalded cat. I installed a tripower and it was amazing. I junked the heads decades later out of ignorance and now wish I hadn't. They are an oddball, half closed chamber, half open chamber. With my 4 speed and 3.55 gears, they sure ran well. Engine had an 066 cam when I pulled it apart.

helmerrock 08-12-2024 09:25 AM

I am running 061’s with 9.5 compression and zero deck. I installed screw in studs also. These run awesome and not even a hint of any detonation.


All times are GMT -4. The time now is 06:04 AM.