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Old 03-30-2002, 12:10 PM   #1
Erl
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Post GMC V6 to a V8 small block

I have a 68 GMC 305V6 3/4 4x4 that needs a 350V8. Is there a difference between the 2WD and 4WD small block frame motor mounts? Will the bell housing require changing?
Thanks in advance
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Old 03-30-2002, 12:50 PM   #2
lukecp
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The bellhousing is exactly the same. Im not sure about the engine mounts though. What is so bad with the V6? Those things are bulletproof tourqe monsters!

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Old 03-31-2002, 12:50 AM   #3
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From the stuff I see under my hood, i think the mounts and the perches need swapped out.
(my '69 GMC which had a 305 and now a 350)

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Old 03-31-2002, 01:12 AM   #4
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just did the samething on my 67 gmc 4x4. u need to swap motor mount stands(cross member)motor mounts . bellhousing will work. might have to move the cross member to the back to holes in the frame where the v6 mounts are now.i found out the hard way that the 2wd v8 cross member would not work in my truck. some other members may have more info for u.
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Old 03-31-2002, 01:14 AM   #5
Longhorn Man
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What cross member you refering to?

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'69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man
I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it.
Need to pick up the one ton Longhorn with a PONTIAC 350/350soon.
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If you need a pic posted, E-mail me at longhornmail@yahoo.com
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Old 03-31-2002, 01:24 AM   #6
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on the v6 the cross member runs at a angle from frame rail to frame rail. the motor mounts mount to it. not really like the v8 mounts that look more like a motor mount stand.hope this makes sense
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Old 03-31-2002, 01:28 AM   #7
Longhorn Man
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Never looked at the mounts for a V-6...guess I need to go to the junk yard and investigate this.

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I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it.
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Old 03-31-2002, 01:33 AM   #8
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for some reason the v6 mounted in the frame rails wierd. i can say i hated the v6 with 456 gears 63 mph top speed with 35 inch tires.

[This message has been edited by bigdog67gmc (edited March 31, 2002).]
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Old 03-31-2002, 10:11 AM   #9
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BigDog,
I really like my truck, but you are correct the V6 and low gearing make it almost unusable in town (Dallas). Did you put a 350 in your truck and did you change the diff gear ratios? Where did you get the motor mounting harware and how did you know it was correct? I am trying to get all the pieces before the motor swap begins.
Thanks
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Old 03-31-2002, 10:38 AM   #10
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If some one can ...post a pic of the V6 4x4 mount...I have yet to see that set up. I did see a 4x4 that originally came with a V6 but didnt pay attention to the mount as it had a 350 in it already.... so I dont remeber if it was chnaged or not. Or email me the pic Thanks. Rod
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Old 03-31-2002, 02:55 PM   #11
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i wanna see 4x4 V^ engine cradle too, should be interesting, then maybe we could figure this out, is probably just a differewnc ein the two engine cradle brackets/pads, im sire the actual cradle itself is probably same as the L6 and V8 one

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Old 03-31-2002, 03:39 PM   #12
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heard motor mount changes need to be made But am keeping my 351 v-6 till she dies torque monster!!!
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Old 04-01-2002, 09:21 AM   #13
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Fast68,
I have had several people try to sell me just the frame motor mounts, others say the cross frame cradle is also needed. I do not see any additional bolt holes to move the cross frame, but this does not mean that a V8 cross frame is the same. It could be shaped differently. The V6 has a complicated bracket on the engine to position the actual motor mount. This leads me to believe that the frame cross cradle is universal. Surely someone knows for certian.
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