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#12486 09/23/2002 7:01 PM | Joined: Mar 2002 Posts: 384 Shop Shark | | Shop Shark Joined: Mar 2002 Posts: 384 | I want to put a 4 speed with granny in my 55.1. I have a 3 speed lite duty in it now. There is no cross member support for my 3 speed tranny. Was there a support for the heavier 4 speed? Is it a cross member or some other sort of bracket? Thanks - Scott
55 1st Chev.
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#12487 09/23/2002 7:19 PM | Joined: Jan 2001 Posts: 687 Shop Shark | | Shop Shark Joined: Jan 2001 Posts: 687 | scott you musta been reading my mind. I was about to post the exact same question. My 66 has the 3 speed/no support in it and I'm going to a significantly larger MY6/89MM 4 speed and wondered if I needed a crossmember.
I think I'm going to be on the safe side and buy one I saw at Golden State parts for 50 bucks. It can only help.
I don't think you can go wrong if you go ahead and get one for your 4 speed. Overkill at best.
-ftyler | | |
#12488 09/23/2002 8:00 PM | Joined: Feb 2001 Posts: 1,897 Member | | Member Joined: Feb 2001 Posts: 1,897 | Yes, if it is more securely mounted, it will make the whole assembly stronger. 
There is enough good in the worst of us and enough bad in the best of us that it does not behoove any of us to criticize the rest of us.
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Be yourself. If you are ever lost, It will be much easier to find yourself if you know who you are!
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#12489 09/23/2002 10:29 PM | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | There was no rear support in 54/55-st for the 1/2 ton truck transmission (unless you had a HydraMatic transmission). The motor mounts and the frame crossbrace for the motor mounts changed in 1954, supposedly making the rear mount for the 3-sp and 4-sp transmission unnecessary.
I have never had one on my 1/2-ton '54 pickup and it had a 4-sp on it from the factory (no holes in the steering column for the 3-sp shifter box).
Tim | | |
#12490 09/24/2002 12:58 AM | Joined: Apr 2000 Posts: 58 Member | | Member Joined: Apr 2000 Posts: 58 | Not sure what you figure to accomplish by using a crossmember with a trans that has no mount for bolting it to. | | |
#12491 09/24/2002 7:12 AM | Joined: Feb 2001 Posts: 1,897 Member | | Member Joined: Feb 2001 Posts: 1,897 |
There is enough good in the worst of us and enough bad in the best of us that it does not behoove any of us to criticize the rest of us.
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Be yourself. If you are ever lost, It will be much easier to find yourself if you know who you are!
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#12492 09/24/2002 7:29 PM | Joined: May 2001 Posts: 13 Junior Member | | Junior Member Joined: May 2001 Posts: 13 | I REPLACED THE 3 SPD TRANNY IN MY 53 W/ A SAGINAW
4 SPD OUT OF AN 82 PONTIAC FIREBIRD AND FABRICATED
A TRANNY X-MEMBER FOR IT BY USING A 1 1/2" SQUARE
TUBING AND BOLTED IT IN USING #8 NUTS AND BOLTS
JUST TO BE ON THE SAFE SIDE...ALOHA | | |
#12493 09/25/2002 7:03 PM | Joined: Mar 2002 Posts: 384 Shop Shark | | Shop Shark Joined: Mar 2002 Posts: 384 | tclederman, or anyone else....What are the proper numbers for the 4 spd original tranny type? The junk yard needs to know. Also any installation tips would be helpful. - Thanks for all replies!
55 1st Chev.
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#12495 09/26/2002 3:38 PM | Joined: Mar 2002 Posts: 384 Shop Shark | | Shop Shark Joined: Mar 2002 Posts: 384 | Wow!!!That is more than I could have hoped for....
Thanks much Richard!
55 1st Chev.
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#12496 09/26/2002 9:15 PM | Joined: Jun 2000 Posts: 2,773 'Bolter | | 'Bolter Joined: Jun 2000 Posts: 2,773 | SM420 (reverse is to the left) does not require a rear mount. All support is through the bell housing. If you get the SM465 (reverse is to the right) which is a newer tranny, a rear mount is required. You can use your existing bell housing, but you will have to machine to enlarge the cutout. Bolts are in the same place, though. Either one is a good box, parts for the SM465 are easier to get, they were built from about 67 to 79. Iirc, they also take different pressure plates.
Fred
52 3600
69 C-10
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#12497 09/27/2002 4:47 AM | | Anonymous Unregistered | | Anonymous Unregistered | "There was no rear support in 54/55-st for the 1/2 ton truck transmission (unless you had a HydraMatic transmission)." I dont agree TC. I just parted out a 54 1/2 ton with a 4 speed & it did have the rear trans. crossmember . These mounts are avaliable if you put a want ad in the Swapmeet section  | | |
#12498 10/02/2002 6:29 PM | Joined: Mar 2002 Posts: 384 Shop Shark | | Shop Shark Joined: Mar 2002 Posts: 384 | I thought it was a simple question. Why is it I can't get a simple answer? Do they have a cross member supporting the 4 spd. tranny SM420? How can this be a point of contention? Thanks!
55 1st Chev.
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#12499 10/02/2002 7:13 PM | Joined: Jan 2001 Posts: 45 Member | | Member Joined: Jan 2001 Posts: 45 | Simple Answer
1955 no mount
1947-54 had a mount
So in your case being a 1955 no mount
no crossmember for 1955 sm420
Mike | | |
#12500 10/02/2002 10:02 PM | Joined: Mar 2002 Posts: 384 Shop Shark | | Shop Shark Joined: Mar 2002 Posts: 384 |
55 1st Chev.
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#12501 10/03/2002 5:53 PM | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Being pedantic (again):
Both the 1954 and 1955-first-series 1/2 ton truck had no transmission mount unless it had a HydraMatic transmission.
This correction is no change to the information pertinent to scdascda but is a slight change to the Simple Answer above.
Tim | | |
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