05-06-2021, 12:41 PM | #1 |
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Location: Amarillo, Texas
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Pontiac swap
I apologize for posting the same question again, but I still have no clear answer. I want to install a 76 Pontiac 400 in my 69 GMC originally 305 V6. I really want this to look factory and have found vague references as to what frame "towers" to use but would love to hear from someone who has done this w/details.
THANX
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05-06-2021, 01:24 PM | #2 |
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Join Date: Mar 2003
Location: Colfax-California
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Re: Pontiac swap
short search found this
https://67-72chevytrucks.com/vboard/...ac+engine+swap |
05-06-2021, 01:46 PM | #3 |
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Re: Pontiac swap
I reread your older post and it seems you are looking for some OEM parts to make the transplant. I don't know if this is possible. Olds used some Pontiac motors in cars (and/or vice-versa), but I can't help but think that those mounting parts would not bolt up in a truck. I'd love to know better, if you have the info.
But, I did put a Pontiac 400 in my truck. I think the block was a 70 or 71. Here's the story...I went to buy some C10 parts from a guy and one of the longhorn trucks had a Pontiac 400 in it...loving the Pontiac motors, I bought the motor, trans, and mounts...many years later, I have a Pontiac 400 C10. I know very little about the parts I purchased. The rubberized mounts are definitely Pontiac. I think the towers are Pontiac too, maybe late 70’s firebird mounts. The Pontiac 400 that I purchased out of the longhorn was a YX block which may help determine what car the tower brackets came from IF the Pontiac parts all came from the same donor car. I would estimate that the motor/fan sits about an 1 to 1-1/2" higher that the original Chevy 350 as I had to relocate the Chevy fan shroud upwards in order for it to work properly. There is only one fabricated piece and it is the flat plate that connects the top of the tower to the frame. Here's some photos...
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He who is without oil shall throw the first rod. Compressions 8.7:1 1972 C10 1976 C10 (parts truck) 1985 K20 |
05-06-2021, 01:48 PM | #4 |
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Re: Pontiac swap
Flat plate that connects the top of the tower to the frame photo...
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He who is without oil shall throw the first rod. Compressions 8.7:1 1972 C10 1976 C10 (parts truck) 1985 K20 |
05-06-2021, 01:55 PM | #5 |
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Re: Pontiac swap
I just got mine on the road a few weeks ago. Here's some encouragement...
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He who is without oil shall throw the first rod. Compressions 8.7:1 1972 C10 1976 C10 (parts truck) 1985 K20 |
05-06-2021, 02:07 PM | #6 |
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Re: Pontiac swap
Side notes:
1.) I had to move my V8 x-member and shift linkage bracket back to the more rear set of holes in the frame to accommodate the TH400, but all the auto shift linkage parts worked fine. 2.) You may want to put the battery on the other side so the battery cable is not so long and snaking around. I bought the auxiliary battery box and tossed the passenger side one as it was toast.
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He who is without oil shall throw the first rod. Compressions 8.7:1 1972 C10 1976 C10 (parts truck) 1985 K20 Last edited by sick472; 05-06-2021 at 02:10 PM. Reason: typo |
05-06-2021, 02:41 PM | #7 |
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Re: Pontiac swap
My thoughts are to change the towers over to 73 and up. Then you could use the frame brackets and motor mounts from almost any Pontiac V8. Probably best to get a donor car for radiator, brackets, hoses, wiring etc.
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05-08-2021, 10:41 AM | #8 |
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Re: Pontiac swap
I need to save this thread. Great info. I have a 327 built for my '67 GMC project, but still toy with the idea of going Pontiac. GMC began use of V8s in '67 but I think it was later in the year. A GMC/Pontiac marriage just seems natural
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05-08-2021, 12:25 PM | #9 |
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Re: Pontiac swap
Love this. Having owned several Pontiacs over the years, I appreciate the ease of working on, the appearance, and the power of a traditional Pontiac V8.
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05-08-2021, 04:20 PM | #10 | |
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Re: Pontiac swap
Quote:
Way better than the 60s Pontiac mounts. I have always thought a Pontiac would be a great truck engine because they make a lot of torque. Greg
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