Sm465 swap

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

K201979

Full Access Member
Joined
Oct 22, 2018
Posts
879
Reaction score
863
Location
Winona, missouri
First Name
Hippie
Truck Year
1979
Truck Model
K20
Engine Size
350ci
I hear you need driveshafts. I've got longbed slip shaft on my earlier pic. It's the 2 shaft version not one single though
This kind?

You must be registered for see images attach
 

hoagster

Full Access Member
Joined
May 16, 2017
Posts
1,393
Reaction score
3,436
Location
California
First Name
Mike
Truck Year
1973, 2000
Truck Model
K10, 1500
Engine Size
5.3l
I took so many pictures when I was tearing down my truck. Except the Z-Bar area totally missed that section. This is what it looks like at the moment. still have a way to go and your pictures helped.

You must be registered for see images attach


You must be registered for see images attach
 

K201979

Full Access Member
Joined
Oct 22, 2018
Posts
879
Reaction score
863
Location
Winona, missouri
First Name
Hippie
Truck Year
1979
Truck Model
K20
Engine Size
350ci
Im glad. Looks like the only thing you're missing is the spring from the fork to the frame. Lookin’good:waytogo:
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,869
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
You must be registered for see images attach
You must be registered for see images attach
 

K201979

Full Access Member
Joined
Oct 22, 2018
Posts
879
Reaction score
863
Location
Winona, missouri
First Name
Hippie
Truck Year
1979
Truck Model
K20
Engine Size
350ci
You must be registered for see images attach
You must be registered for see images attach
I thought those were only used in 2wd applications. Mine looks like the one in my picture and has a 67” working length. What is that in?
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,869
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
77 k25 4wd longbed. sm465 with a np205
 

K201979

Full Access Member
Joined
Oct 22, 2018
Posts
879
Reaction score
863
Location
Winona, missouri
First Name
Hippie
Truck Year
1979
Truck Model
K20
Engine Size
350ci
77 k25 4wd longbed. sm465 with a np205
Interesting. Probly would fit, but with a lifted truck, i imagine it would kill the angle at the pinion. Plus more ujoints, splines, and a carrier bearing to maintain and worry about failing.
 

Preston Tucker

Full Access Member
Joined
May 13, 2020
Posts
106
Reaction score
50
Location
Maine
First Name
Preston
Truck Year
1974
Truck Model
K20
Engine Size
350
@K201979 Where you able to use the same transmission cross member when you swapped from the th350 to the sm465? I am in the middle of a swap in my 74 and coming out is a th350 paired up with an np205. Going in is a sm465 paired up with a np241c aluminum case out of an 87 with hydraulic linkage.
I know i need to move the cross member 2 3/4 of an inch back. Its a 74 so it doesn't have the extra 4 holes drilled for this accommodation like the later ones had. I just don't know if i need a different cross member.
 

K201979

Full Access Member
Joined
Oct 22, 2018
Posts
879
Reaction score
863
Location
Winona, missouri
First Name
Hippie
Truck Year
1979
Truck Model
K20
Engine Size
350ci
@K201979 Where you able to use the same transmission cross member when you swapped from the th350 to the sm465? I am in the middle of a swap in my 74 and coming out is a th350 paired up with an np205. Going in is a sm465 paired up with a np241c aluminum case out of an 87 with hydraulic linkage.
I know i need to move the cross member 2 3/4 of an inch back. Its a 74 so it doesn't have the extra 4 holes drilled for this accommodation like the later ones had. I just don't know if i need a different cross member.
I used the same one. I think it depends on the hight of the mounts on the adapter. @bucket or @HotRodPC might no more. I did have to slide mine back but the holes were there. I thought i was going to have to drill one of them but it was just caked full of mud. There was a whole thread on here about crossmembers. Ill see if i can find it. Any other questions, just ask. Im glad to help. This is the crossmember and adapter i used:

You must be registered for see images attach
 

K201979

Full Access Member
Joined
Oct 22, 2018
Posts
879
Reaction score
863
Location
Winona, missouri
First Name
Hippie
Truck Year
1979
Truck Model
K20
Engine Size
350ci
I cant find the thread on crossmembers but if i do i will post it.
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,446
Reaction score
28,348
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
If the adapter is from the '87, it is the "short foot" style and will require an '85-up crossmember and mount. You can use both styles of crossmember used in the later years. One is a double hump ('85-'86) style and the other is a weird looking wavy one where one side doesn't match the other ('87-'91).

If you can find a '81-'84 tall foot style adapter for a 465/208 combo, you can reuse your original crossmember and mount. The 208 interchanges with the 241... which by the way wasn't used until '89.

You also can use the short foot adapter with the older style crossmember, but it will take some boonrigging.
 

Preston Tucker

Full Access Member
Joined
May 13, 2020
Posts
106
Reaction score
50
Location
Maine
First Name
Preston
Truck Year
1974
Truck Model
K20
Engine Size
350
Well since you said that the 241 wasnt used till 89, it made me wonder so i did some research and it is in fact the crappy 208.:( So would a better option be using my bullet proof 205 that came out of it originally and mate it with the 4 speed? In theory that means all i would need to do is buy a new adapter. ThenI ill be able to use my old drive shafts without altering any of the lengths.
Is that correct?

This is my $75 unit i have to work with.
You must be registered for see images attach


You must be registered for see images attach
 

K201979

Full Access Member
Joined
Oct 22, 2018
Posts
879
Reaction score
863
Location
Winona, missouri
First Name
Hippie
Truck Year
1979
Truck Model
K20
Engine Size
350ci
Well since you said that the 241 wasnt used till 89, it made me wonder so i did some research and it is in fact the crappy 208.:( So would a better option be using my bullet proof 205 that came out of it originally and mate it with the 4 speed? In theory that means all i would need to do is buy a new adapter. ThenI ill be able to use my old drive shafts without altering any of the lengths.
Is that correct?

This is my $75 unit i have to work with.
You must be registered for see images attach


You must be registered for see images attach
To me, the 205 would always be the better option, but i dont think the length will be the same, as far as your driveshafts working. I think you could make the 205 work with the right adapter and coupler that mates the shafts. That 74 205 will use the “racetrack” bolt pattern so you will need the adapter like in my picture. The newer 465’s, i think, are 32 spline iirc,(older are 10 spline), and the 205 mated to the 350 should be 27 spline, i think. So with a 27-32 spline coupler and a racetrack pattern adapter you should be able to make it work, i think:).
 

Forum statistics

Threads
44,168
Posts
950,805
Members
36,286
Latest member
goodwrenchca
Top