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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 76 k10 on August 04, 2009, 06:13:17 pm

Title: th350 to sm465.
Post by: 76 k10 on August 04, 2009, 06:13:17 pm
I am doing this swap on my truck and i have all the parts to do it. i was jw how long do you think it will take me to do this. i no these trucks pretty good and i have all the tool to do so and i no how everything gos togather and how take it off and put it pack on. i just need a idea on how long my truck is gonna be down for
Title: Re: th350 to sm465.
Post by: zieg85 on August 04, 2009, 07:05:49 pm
A good days work is my guess.  My least favorite part is the clutch pedals/under dash stuff.  Hope you thought of the rise in the hump when using the SM465.
Title: Re: th350 to sm465.
Post by: swcu_21 on August 04, 2009, 08:56:56 pm
I made a similar change to the sm465 and i had to put a new piece of sheet metal in, the old hump was too shallow. Plan on taking the seats out too or you will have to cut up your carpet.

Good Luck
Title: Re: th350 to sm465.
Post by: VileZambonie on August 04, 2009, 10:06:24 pm
I am curious why you would want to go to the SM465?
Title: Re: th350 to sm465.
Post by: 76 k10 on August 04, 2009, 11:34:07 pm
I am curious why you would want to go to the SM465?
well cuz its strong and has that low 1st gear. and the motor thats in my truck now has no low end and i kinda want that granny gear. o ya and im building a 427 for my truck and i need something that will hold up you no. but is the a reson y i should do this swap? jw
Title: Re: th350 to sm465.
Post by: 76 k10 on August 04, 2009, 11:36:09 pm
I made a similar change to the sm465 and i had to put a new piece of sheet metal in, the old hump was too shallow. Plan on taking the seats out too or you will have to cut up your carpet.

Good Luck
what carpet? lol its a mud truck.
Title: Re: th350 to sm465.
Post by: Irish_Alley on August 05, 2009, 02:08:11 am
what ratio you have in the rear?
Title: Re: th350 to sm465.
Post by: VileZambonie on August 05, 2009, 06:39:41 am
I hate that trans and find 1st gear useless for anything other than off road creeping or pulling something like a stump out lol. I would look at your rear gear ratio first.
Title: Re: th350 to sm465.
Post by: Irish_Alley on August 05, 2009, 10:42:15 am
I hate that trans and find 1st gear useless for anything other than off road creeping or pulling something like a stump out lol. I would look at your rear gear ratio first.
x2
i have it in my 79 4x4 the gearring sucks even in the mud
Title: Re: th350 to sm465.
Post by: zieg85 on August 05, 2009, 05:36:39 pm
I hate that trans and find 1st gear useless for anything other than off road creeping or pulling something like a stump out lol. I would look at your rear gear ratio first.

I love mine, could have something to do with my 454 engine and 3.21 gearing.  Gets the heavy loads moving without any clutch wear.  Truck still has its original clutch after 140K miles and about 60K of them pulling a 35 ft 80's vintage 5th wheel.
Title: Re: th350 to sm465.
Post by: swcu_21 on August 05, 2009, 06:01:54 pm
Sorry forgot a lot of posters here frequent the mud.

I don't care for mine. It was a quick fix when my automatic went, but thats it. Even when i lived in the country I rarely used the compound low and now I never do. With the 2.73 rear end and a slightly modified 350 the RPMs at 70 are too high for me. I would try a 4 speed with a little higher first and closer gears for mud.
Title: Re: th350 to sm465.
Post by: Captkaos on August 05, 2009, 06:23:35 pm
should be about a days works to swap it out, maybe 1.5.

I love that transmission.
Title: Re: th350 to sm465.
Post by: 76 k10 on August 05, 2009, 10:42:16 pm
im running 12 bolt with 4.11s and a dana 44 with 410s
Title: Re: th350 to sm465.
Post by: VileZambonie on August 05, 2009, 11:56:10 pm
I think I need to do a simple write up on how to calculate driveline overall ratio's. The Granny Tranny has never proven to me to be a useful practical trans for any street use. I don't see why anyone would favor this trans over all of the other options out there.
Title: Re: th350 to sm465.
Post by: frogman68 on August 06, 2009, 07:08:27 am
I think I need to do a simple write up on how to calculate driveline overall ratio's. The Granny Tranny has never proven to me to be a useful practical trans for any street use. I don't see why anyone would favor this trans over all of the other options out there.


I like it for the simple reason that someone that doesnt know how to drive a stick can just dump the clutch in first and it wont die
Title: Re: th350 to sm465.
Post by: Irish_Alley on August 06, 2009, 04:57:21 pm
is this truck only being used in the mud or on the road? also what size tires you running?
Title: Re: th350 to sm465.
Post by: zieg85 on August 06, 2009, 05:31:10 pm
http://www.5speeds.com/rpm.htm  has an excellent RPM calculator program.  It is free to download and lists common transmissions/tire sizes.  It is a little confusing to use but just go across the top and plug in the numbers for all that they ask and it will tell you the RPM based on what final drive gear you have. 
Title: Re: th350 to sm465.
Post by: Irish_Alley on August 06, 2009, 08:20:53 pm
heres one you don't have to download http://www.idavette.net/tech/ratioc.htm
Title: Re: th350 to sm465.
Post by: werewolfx13 on August 09, 2009, 11:48:48 am
Having spent some time behind the wheel of a high geared (low 2.xx numerical gears) F-150 w/ a 3+OD toploader and 35" MTX's, driving a truck with an sm465 is a welcomed experience, IMO.
Title: Re: th350 to sm465.
Post by: zieg85 on August 09, 2009, 12:53:44 pm
Having spent some time behind the wheel of a high geared (low 2.xx numerical gears) F-150 w/ a 3+OD toploader and 35" MTX's, driving a truck with an sm465 is a welcomed experience, IMO.

Had one of those transmissions in a 86 Bronco, what a dog from 2nd to 3rd.  Wonder what Ford was thinking when they came up with that one....
Title: Re: th350 to sm465.
Post by: Antti on August 09, 2009, 01:57:37 pm
Having spent some time behind the wheel of a high geared (low 2.xx numerical gears) F-150 w/ a 3+OD toploader and 35" MTX's, driving a truck with an sm465 is a welcomed experience, IMO.
I agree to that. My other truck has an A833 OD w/ hi gears, and it sucks, even in normal takeoffs at intersections. Starting at a slope or trying to pull something is horrible. I don't think a truck should be like that.

I love my other truck's sm465 in tight places, since both the 1st and the reverse are low. At normal intersections I just start with the 2nd gear. It has 33"s and 3.73:1. I cruise it usually about 55mph.