« previous next »
Pages: 1 2 [3]   Go Down

Author Topic: GMC 270H Head  (Read 13402 times)

0 Members and 1 Guest are viewing this topic.

Offline maguromic

  • Hero Member
  • *****
  • Posts: 1736
    • http://www.barringtontea.com
Re: GMC 270H Head
« Reply #30 on: March 06, 2012, 09:47:43 PM »
Buddy, Its Mike Kirby, Kay Sissell passed away some time ago and Mike was Kay's partner and carries on.  By the way you can get an iron head to flow like a 12mport with some work.  All the records in XO and XXO that the BMR coupe set were with  an iron head.

I found these of the exhaust and intake on my computer of the head I cut up.  Tony


« Last Edit: March 06, 2012, 10:07:00 PM by maguromic »
Logged
“If you haven’t seen the future, you are not going fast enough”

Offline 38flattie

  • Hero Member
  • *****
  • Posts: 2169
    • http://www.flatcadracing.org/
Re: GMC 270H Head
« Reply #31 on: March 07, 2012, 09:41:26 AM »
Tony, thanks for the correction on Mike Kirby's name!

Those pics are helpful!
Logged
With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925

You can't make a race horse out of a pig. But if you work hard enough at it you can make a mighty fast pig. - Bob Akin

http://www.flatcadracing.org/
http://youtu.be/89rVb497_4c

Offline NArias3

  • Full Member
  • ***
  • Posts: 144
  • Arias Components
    • Arias Components Engineered
Re: GMC 270H Head
« Reply #32 on: January 09, 2014, 01:06:00 PM »
Hey Fellas-
I need the chamber volumes of these GMC 270 heads.  There appears to be big difference in cc's (~54.0) between the "Open" and "D-Shape".

Can you enlighten me on the years and corresponding part numbers?  Also the similarities between the 228/248/256 inchers.

Thanks,
Nick III.
Logged
SCTA Gear Grinder.

https://ariascomponents.com

Offline dw230

  • Hero Member
  • *****
  • Posts: 3168
Re: GMC 270H Head
« Reply #33 on: January 09, 2014, 08:36:02 PM »
Ask your Dad, he probably has those numbers bouncing around in his head.

DW
Logged
White Goose Bar - Where LSR is a lifestyle
Alcohol - because no good story starts with a salad.

Don't be Karen, be Beth

Offline jimmy six

  • Hero Member
  • *****
  • Posts: 2788
Re: GMC 270H Head
« Reply #34 on: January 11, 2014, 03:08:43 PM »
38.. Your planning a supercharger, use a 302 head. It's easier to plan your piston top when your not needing to fill the head chamber for compression. A stock 302 has 7.5 -1 C.R. by the GM manual. Personally the flatter the top the better.

As for shrouding my choice is a 1.94 intake and 1.60 exhaust valves. Been using Chev small block valves for years and larger diameter springs after machining the spring seats to 1.55"+. Isky has the tool. Comp cams lists springs at 2" height making this pretty easy. Valve lift is for you to figure out after flow tests. Remember to consider C.I. per cylinder and RPM you are planning.

Nick3. There is a lot of difference between the 2 heads in CC's. I have the number for my H head but it's been cut a lot. ..........JD

PS:Keeping H and 302 heads, 302 blocks, 270/302 cranks, from the hoarders. (You can divey them up when I die, mamma knows what they are worth :-D)
Logged
First GMC 6 powered Fuel roadster over 200, with 2 red hats. Pit crew for Patrick Tone's Super Stock #49 Camaro

Offline RichFox

  • Hero Member
  • *****
  • Posts: 2663
Re: GMC 270H Head
« Reply #35 on: January 11, 2014, 04:39:49 PM »
I always used 302 heads. And the same valves as Jim. I never could see the point in paying for the H head.
Logged
Pages: 1 2 [3]   Go Up
« previous next »