Author Topic: Header Options for a 1975 GMC Jimmy with a 454  (Read 14171 times)

Offline Mike Phillips

  • Junior Member
  • ***
  • Posts: 626
Header Options for a 1975 GMC Jimmy with a 454
« on: June 26, 2009, 10:39:53 pm »
Anyone been there done that?

I bought a set of block hugger headers for a 454 off Craigslist for $65.00 and when I just now tried to install them I find they don't fit.  The passenger side header hits the motor mount and the frame and the driver's side hits the frame.

I need a set of budget headers that will 100% fit this application.

I'm not sure the first year a big block was available in the Jimmy/Blazer so this makes it a little hard to look up an application part number.

Any suggestions?


:)

Offline 82k5diesel

  • Newbie
  • Posts: 48
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #1 on: June 26, 2009, 11:33:46 pm »
Hedman headers make a set 68-81 pu/blazer 4wd bbc. List for 120 bucks in jegs catalog pn 500-69110.

Offline Mike Phillips

  • Junior Member
  • ***
  • Posts: 626
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #2 on: June 27, 2009, 02:06:36 am »
Hedman headers make a set 68-81 pu/blazer 4wd bbc. List for 120 bucks in jegs catalog pn 500-69110.

Thanks!

Checked out the above headers on Jegs website and they offered up the Hooker, Jeg's brand and Dynomax equivelents which is a nice feature on any online store.

So while this thread is up and going, anyone have any experience or opinions on which of the 4 sets provide the best value and performance?

Hedman $153.99
http://www.jegs.com/i/Hedman/500/69110/10002/-1


Jegs inhouse brand: $99.99
http://www.jegs.com/i/JEGS/555/30059/10002/-1


Hooker: $189.99
http://www.jegs.com/i/Hooker/520/2454/10002/-1



Dynomax:   $132.99
http://www.jegs.com/i/Dynomax/289/85022/10002/-1



I need them yesterday. 


 :(
« Last Edit: June 27, 2009, 10:07:01 am by Mike Phillips »

Offline Mike Phillips

  • Junior Member
  • ***
  • Posts: 626
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #3 on: June 27, 2009, 12:09:57 pm »
Called Jegs, with normal shipping the soonest I can get the headers is on Thursday, for about $40.00 they can get them to me on Wednesday.


 :(

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19174
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #4 on: June 27, 2009, 12:30:02 pm »
Here's the best cheapies imo from Jegs

http://www.jegs.com/i/Hedman/500/69820/10002/-1

Don't bother with an uncoated header
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Mike Phillips

  • Junior Member
  • ***
  • Posts: 626
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #5 on: June 29, 2009, 10:35:52 am »
Thanks for the link to the Headman headers, they look like a good deal for my application.  Just ordered them, they'll be here on Thursday.




The Jeg's Tech guy looked at the foot notes and said that I must use the big block mounting hardware in order for them to fit?

I used the steel block mount from a 1986 Suburban that had a 454 in it but I didn't think to remove the frame stands out of the Suburban and see if they will fit my 1975 Jimmy.

Since I already have the motor into the Jimmy I guess I'll wait till Thursday to see if they fit, if they don't it looks like I'll have to pull the motor, swap out the frame stands and then see if they'll fit.


Anyone ever been down this road an already know the end of the story?

Ugh....

 :(
« Last Edit: June 29, 2009, 10:37:55 am by Mike Phillips »

Offline Mike Phillips

  • Junior Member
  • ***
  • Posts: 626
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #6 on: June 29, 2009, 10:39:57 am »
These Hedman headers come with a Ball & Socket style collector?  Never seen this before?  As long as this design works that's all that's important.




 ???

Offline ccz145a

  • Senior Member
  • ****
  • Posts: 1393
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #7 on: June 29, 2009, 11:23:35 am »
That is supposed to have superior sealing characteristics... no gasket just lots of surface area to prevent leaks and a wider angle allowable.
1975 C10 Silverado LWB, 454CID, TH400, 10bolt 3.42
11MPG Downhill w/tailwind (but there ain't no hills here)

Offline Mike Phillips

  • Junior Member
  • ***
  • Posts: 626
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #8 on: June 29, 2009, 12:11:25 pm »
Here's the clearance I have to work with using the stock frame stands.







Here's the Suburban with the original frame stands still in it.




Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19174
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #9 on: June 29, 2009, 05:04:30 pm »
You shouldn't have any serious issues. I would recommend you disconnect the battery, pull your spark plugs, disconnect the dipstick tube and bubble wrap the headers before you put them in though so you don't scratch them all up.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Mike Phillips

  • Junior Member
  • ***
  • Posts: 626
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #10 on: July 04, 2009, 03:50:15 pm »
***Update***

The Hedman headers arrived Thursday.

Had to use a 4" angle grinder to cut off a sliver of frame on the driver's side in order to get them to fit.  There on now but there wasn't much wiggle room.  I'll add a picture later.

:)

Offline Mike Phillips

  • Junior Member
  • ***
  • Posts: 626
Re: Header Options for a 1975 GMC Jimmy with a 454
« Reply #11 on: July 04, 2009, 05:29:22 pm »

Tight fit...