1976 GMC Straight 6

[RMac5]

My son has a 76 with a straight 6 motor. The motor overheated and cracked the head. I’m being told, by the mechanic I trust, that the exhaust manifold is integrated into the head. He’s having a hell of a time finding this part. Does any of this sound right? I hope I have explained it correctly or I have conveyed it correctly. I’m not familiar with this motor, I grew up with a 77 with a 350.

not sure where to look for this part or exactly what to call what I’m looking for. This truck has 3 on the tree and no power steering or AC. He loves this truck but I’m not sure how much to spend getting it back up and running. Any help finding this part or suggestions on replacing the entire motor. Thanks for any suggestions or pointers.

 

[RMac5]

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Here is the beast!

 

[Bextreme04]

Thats a great looking truck! I'm not big on the I-6, but there are quite a few 6 banger enthusiasts on here that should be able to help. It's my understanding that the integrated head engines are not great. You can swap in a non-integrated head or find a full replacement 250 or 292 to just swap it out. I see them pop up around me all the time for a few hundred dollars.

 

[Memaloose]

I had an integrated head on a 250 repaired about 20 years ago, never had any problems with it again. I took it to NAPA in Fairbanks, AK, they shipped it to Seattle for the repair, I had it back in a month.
Mine was in an '81 Custom Deluxe SWB C10, 250, 3 speed on column, no power steering or brakes either. I ran that truck as a daily driver for 11 years. I bought it used for $1400 and sold it 11 years later for $2500 One of the most reliable vehicles I ever drove, that's a good setup, I'd keep the 250 in it. Like he said, you can convert to a conventional head if you can't get the integrated one done.

 

[RMac5]

Thanks for the info, I spoke with a parts locator yesterday and she’s thinking she may have found one. If not I will start looking for a motor. Thanks again!