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01-08-2023, 10:38 PM | #1 |
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3 speed behind a 292
Is a 292 too much for the 3OTT?
The 292 was usually with a sm420 or sm465 right? I have a 1/2 ton with a bad 250. I can either put in a 307 or a 292. Any suggestions? The 6 swap would be much easier. Posted via Mobile Device |
01-09-2023, 03:19 AM | #2 |
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Re: 3 speed behind a 292
No the 3-speed was available with the larger motors including the 350ci.
Listed as HD, maybe others will know how to ID the non-heave duty 3-speeds? It appears the HD 3-speed was even an option behind the 400 V8. List below is from 1971 C10; Last edited by Accelo; 01-09-2023 at 02:38 PM. |
01-09-2023, 07:08 AM | #3 |
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Re: 3 speed behind a 292
I might be a little biased, but I say go with a 292. Love mine that I swapped from a 250.
Just be aware the 292 takes a different passenger side motor stand that can be hard to find sometimes.
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67 C10 283 T5 swapped longbed fleetside = wife's daily driver 67 C20 292 (originally a 250)4speed longbed fleetside w/original wooden bed=my project truck 67 C10 283+.060 (so a 292 as well)T5 swapped longbed fleetside=my DD 72 C1500 Sierra Grande 350 TH350 longbed fleetside=wife's fair weather truck Can you tell we are fans of longbed fleetsides & 67s Chris |
01-09-2023, 08:46 AM | #4 |
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Re: 3 speed behind a 292
I've had two big block trucks with 3spd transmission. The 3spd was standard transmission in the 4wds, even K/20s.
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"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
01-09-2023, 10:35 AM | #5 |
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Re: 3 speed behind a 292
My truck came with a 250 and an automatic. I switched to the 292, you will need a different frame mount on the right side only. The theromstat housing is a little different than the 250 too. Also if you have PS on the 250, it will not fit the 292, other than that your good to go. Picture shows difference in housing.
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01-09-2023, 05:12 PM | #6 |
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I’ve got the passenger side mount. Everything else should line up where the 250 sat.
One other question, can I use the 250 radiator for the 292? Posted via Mobile Device |
01-10-2023, 12:26 PM | #7 |
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Re: 3 speed behind a 292
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01-10-2023, 02:02 PM | #8 |
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Re: 3 speed behind a 292
And you put AC in it, right? Did you install a fan shroud? I don't recall all the details. Just that I really like that truck!
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01-10-2023, 08:02 PM | #9 |
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Re: 3 speed behind a 292
Years ago I was given a 68 GMC 1500 with a blown 250. I located a 292 just because I figured why put a 250 back in when the 292 would fit ? I never could keep the crappy Chinese rubber engine mounts from ripping out. The three on the tree and stock 250 rear end imo did not play well together.
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01-12-2023, 11:01 AM | #10 |
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Re: 3 speed behind a 292
As you can see it has a full fan shroud, I bought this truck out of southern CA about 6 years ago and it came with a 3 core radiator and the shroud. Yes I added the vintage air, a 200-4R and the PS.
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01-12-2023, 11:59 AM | #11 | |
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Re: 3 speed behind a 292
Quote:
We had a 292 bored to 305 cu in, with three Rochester 2bbls (and Pontiac tripower progressive linkage) with a Saginaw four speed behind it, and it was fine. K
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01-12-2023, 03:21 PM | #12 | |
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Re: 3 speed behind a 292
Quote:
I replaced the 3spd with a SM465 and put 3.54 gears in the DANA. The new, longer front half of the drive shaft is more appropriately sized. The truck is much happier with the truck 4spd.
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'67 GMC 2500, 292, 4spd, AC |
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01-12-2023, 03:41 PM | #13 |
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Re: 3 speed behind a 292
A 292 bored .060 is 301 cubes, which is what I have. You have to go .090" to get 305.23 cubes. I've seen one that was .080" over that ran for years, but eventually it cracked a cylinder bore.
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'67 GMC 2500, 292, 4spd, AC |
01-12-2023, 10:40 PM | #14 |
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Re: 3 speed behind a 292
Good info here. The 292 I have was out of a grain truck. 28k miles on the truck Score! Are the rubber mounts different on the grain than the c10/20/30?
I’d prefer to use the OEM mounts instead of new. Posted via Mobile Device |
01-12-2023, 11:31 PM | #15 | |
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Re: 3 speed behind a 292
Quote:
I have two complete 292ci engines out of the larger grain trucks but I have never looked at the mounts that close. I know one of them has power steering on it. I will have to check them out. I think the block pads would be the same but the frame brackets may be different than the 292ci pickups. I will try to remember to check them out. LockDoc .
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01-24-2023, 08:49 PM | #16 | |
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Quote:
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01-24-2023, 09:36 PM | #17 |
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Re: 3 speed behind a 292
I wrote myself a note to do this tomorrow. Thanks.... LockDoc
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Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
01-25-2023, 01:27 PM | #18 |
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Re: 3 speed behind a 292
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The rubber pad mounts are different for the C40, 50, 60 292 but the block brackets are the same, so the C10, 20, & 30 rubber pad mounts will work with the C40, 50, & 60 block brackets. The big truck rubber pad mounts are about 3 x 5 inches and mount horizontally. 3 Bolt holes on the top side and 1 center bolt on the bottom. I will remove one of them and update this with a picture when I come back in later.... EDIT: Here are the pictures. 1st picture is front of big truck rubber mount. Second is the back. Third shows how holes line up with a C10, 20, 30 rubber mount, and 4th is the block bracket. The bottom hole in the block bracket has a weld nut in it. LockDoc .
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Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - Last edited by LockDoc; 01-25-2023 at 04:41 PM. |
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