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Trying to put a Pontiac GTO 400 engine in my Chevrolet truck.

23 messages,  Last post on Jan 30, 2013 at 8:26 PM

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What is this discussion about? Chevrolet C/K 10 Series, Performance Mods, Truck

Messages Page 2 of 3

#4 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [oldfixerupper] by 0patience

Sep 05, 2010 (12:20 pm)

Replying to: oldfixerupper (Sep 04, 2010 8:43 pm)
You'll have to modify the engine mounts, most probably have to move the transmission crossmember and possibly have to cut or lengthen the driveline.
While it can be done, you would be far better off to take mr shiftirght's suggestion.
 
We've put a 455 in a 70 chev pickup, but it was a lot of work and to be honest, I wouldn't do it again.

#5 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [Mr_Shiftright] by isellhondas

Sep 06, 2010 (11:39 am)

Replying to: Mr_Shiftright (Sep 05, 2010 8:15 am)
Excellent advise.
 
That was never a "GTO " engine. The 326's came in Le Mans and lesser models.
 
It wouldn't be worth the trouble and headaches that would be involved.

#6 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [isellhondas] by andre1969

Sep 06, 2010 (2:03 pm)

Replying to: isellhondas (Sep 06, 2010 11:39 am)
That was never a "GTO " engine. The 326's came in Le Mans and lesser models.
 
Yeah, that's what I thought. I know there was a wussed-down version of the GTO in later years, but at least it was still a 400 V-8. I think it was a low-suds 2-bbl version designed to run on low-octane fuel. Basically, the credit engine that they offered on the Catalina?
 
I do always get fascinated by these engine swaps mother nature never intended, though. But, they should only be done if you have money to spare, and don't care about taking a loss.

#7 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [andre1969] by isellhondas

Sep 06, 2010 (2:30 pm)

Replying to: andre1969 (Sep 06, 2010 2:03 pm)
Someone in these forums was buying one of those wimpy GTO's awhile back.
 
I never understood why that would have made such a thing or why anyone would have bought one. It's either a GTO or it's not.

#8 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [isellhondas] by num1pontiacman

Apr 09, 2011 (10:52 am)

Replying to: isellhondas (Sep 06, 2010 2:30 pm)
I know this is late and I did just find this thread but I have been putting Pontiac engines in 60-87 chevy/GMCs for a long time. There are componebts made that make it a bolt in deal. NO, the cross members don't need to be moved and NO it isn;t a hassle. A 70 or newer engine block is the most easy bolt in.
Pontiacs bolt right in just like a weak kneed chevy small block. Differance is tha TORQUE for any stock pontiac is far beyond any chevy mouse motor.
NO, a 326 can not be bored to a 400.
I have detailed build photos showing a 400 hp 413 ft/torque 350 pontiac motor in a 79 GMC that is used to pull a 2 car car trailer. Bolted right in with NO fab work necessary.

#9 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [num1pontiacman] by Mr_Shiftright HOST

Apr 09, 2011 (11:22 am)

Replying to: num1pontiacman (Apr 09, 2011 10:52 am)
The original poster was asking about putting in an old 326 motor (??) of dubious origin and specs, so that's where our advice was directed towards possibly a Chevy crate engine. He didn't mention access to other Pontiac engines at the time. The Pontiac 350 is not an engine most people want, except maybe the earlier 68-70 ones, but in the right hands can certainly produce a lot of power. But you have to bore it and you'll need head and camshaft work to get anywhere. This is why I suggested to the poster to just buy crate power.

#10 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [Mr_Shiftright] by andre1969

Apr 09, 2011 (12:32 pm)

Replying to: Mr_Shiftright (Apr 09, 2011 11:22 am)
The Pontiac 350 is not an engine most people want, except maybe the earlier 68-70 ones, but in the right hands can certainly produce a lot of power.
 
After '70 or so, didn't Pontiac mainly look towards the 400 and 455 for their performance engines? I think one reason Chevy put out high-performance 350's was because the 454 was so heavy, so a high-output lightweight smallblock had a lot of uses. But Pontiac didn't do the biglock/smallblock thing. Instead, they had more of a "medium block" design that served all their displacements, so a Pontiac 350 probably wasn't any lighter than a 400 or 455. So, say, if you wanted a 350 hp engine, it was just simpler to get that 350 hp out of a 400 or 455, than a 350.

#11 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [andre1969] by Mr_Shiftright HOST

Apr 09, 2011 (1:20 pm)

Replying to: andre1969 (Apr 09, 2011 12:32 pm)
The bore is too small, and so if you wanted to use a big cam and valves you have to bore and modify for clearance. But it can be done---you can *make* a Pontiac 350 put out impressive horsepower but it requires a good deal of machine work.

#12 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [Mr_Shiftright] by andre1969

Apr 09, 2011 (1:58 pm)

Replying to: Mr_Shiftright (Apr 09, 2011 1:20 pm)
The bore is too small, and so if you wanted to use a big cam and valves you have to bore and modify for clearance. But it can be done---you can *make* a Pontiac 350 put out impressive horsepower but it requires a good deal of machine work.
 
Yeah, a Chevy 350 is a 4.00 bore and 3.48 stroke, while the Pontiac 350 was a 3.88 bore and 3.75 stroke. So the Chevy was more of a revver, but I guess the Pontiac was better for torque?
 
The Chevy 327 had the same bore but an even shorter stroke, so would it have been a better engine to hop up than the 350?

#13 of 23 Re: Trying to put a Pontiac GTO 400 engine in my Chevrolet truck. [andre1969] by Mr_Shiftright HOST

Apr 09, 2011 (2:07 pm)

Replying to: andre1969 (Apr 09, 2011 1:58 pm)
I think it would depend on what you were trying to achieve and how radical you got.

Messages Page 2 of 3

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