1961 gmc 4x4 engine swap

[slugger824]

HELP!!!! I talked myself into buying a 61 4x4 with a 305 v6 in it just because I thought it was cool and before I even bought it won 10 bucks on a few bets that it even existed. Drove it for 1 week or about 75 miles and right as I was turning on my drive I heard a loud knocking in the engine. Shut er down,pulled valve covers seeing nothing wrong. I dropped the pan and the connecting rod caps and found the bearings shot. Mains were next and the same-shot. I started researching the rebuild I was gonna do on it when I was kicked in the pants at what it was gonna cost to just buy the parts I would need not to mention the machining it was going to need to get the crank/cam/heads done. I later found out that the I/E valves are next to impossible to find!! I am not in love with the engine in the first place but now I am convinced of swapping it out to a 350. Question is the trans is a muncie 22 4-speed so I know a bell housing is in order but not sure what else I am going to encounter trying to get the engine in the truck. Has anyone done this swap before and if so tell me its a piece of cake!! Any help is greatly welcome.

[1963c-10]

Are you trying to install a m-22 or is it whats currently in the truck? I believe the sm420 or sm465 was the standard Muncie 4 speed behind the v6.

[padresag]

whatever fits behind your gmc b/housing will fit behind a chevy b/housing of that vintage.
ron

[Captainfab]

You will of course need a bellhousing for a Chevy V8. For the motor mounts, a motor mount crossmember for a '67-'72 4x4 will fit nicely. You'll just have to drill the holes. It seems odd that someone would have put M22 in a 4x4 behind a V6. Those transmissions are hard to come by and $$$$$ when you do.

[padresag]

Originally Posted by Captainfab

You will of course need a bellhousing for a Chevy V8. For the motor mounts, a motor mount crossmember for a '67-'72 4x4 will fit nicely. You'll just have to drill the holes. It seems odd that someone would have put M22 in a 4x4 behind a V6. Those transmissions are hard to come by and $$$$$ when you do.

he could front mount it like a stock 60-62 chev 4 x 4 as he would still have the b/housing mounting(3 points). the problem with that though is it uses the holes for a power steering pump if he want s to install p/s, which was not a stock option. with the use of the later c/member it makes it a lot simpler for p/s
the other point is the height of the early 4 x 4s is that they are not as high as the later ones, one perhaps may have to put a one " spacer(?) under the top part on either side of the frame using the 67-72 m/mount c/member.
http://67-72chevytrucks.com/vboard/s...d.php?t=550856. I know that those measurements are for the middle of the frame, but not sure were the m/mount c/member may go. the 2 wheel drive is not as high as the later ones there
this is what that 67-72 m/mount c/member looks like in a 64


ron

[Captainfab]

We used the '67-'72 crossmember in my son's '63 K10, and it fit just fine.

[padresag]

yes , but the 63 frame is different than the 62.
http://67-72chevytrucks.com/vboard/s...d.php?t=550856.
ron

[Captainfab]

I failed to mention, that the frame under his truck is a '60-'62. I'm thinking it is a '62.

[61K10]

I moded my front horse shoe mount with an aftermarket ps mount--cut the stock mount and welded in the ps piece. site won't let me post a pic.

[TommyDuncan]

If you do the swap don't chuck that v6 right away. Some of us are looking for parts.
Posted via Mobile Device

[padresag]

Originally Posted by 61K10

I moded my front horse shoe mount with an aftermarket ps mount--cut the stock mount and welded in the ps piece. site won't let me post a pic.

you have to resize your pics re link
http://67-72chevytrucks.com/vboard/s...d.php?t=589138
ron

[1963c-10]

Id be interested to know how the v6 like the M-22 behind it.

[slugger824]

Thanks a lot for all the posts. I was incorrect as you said 1963c-10 about the trans. It is a sm 420.I had a neighbor look at it and then was corrected by him as well. OK I see now that it isn't going to just slide right in and includes some mods to the framing/mounts etc. I was hoping that it wouldn't require things like that. I just don't have the tools or knowledge to do it. I may be rebuilding the 305 after all.

[markeb01]

I don’t know anything about 4x4’s, but the following link shows how I replaced my 305 V6 with a 350 Chevy in my 1960 GMC. 60-62 frames are the same:

http://67-72chevytrucks.com/vboard/s...d.php?t=369663

Welcome to the forum, and good luck on whatever you decide to do.

[slugger824]

Originally Posted by markeb01

I don’t know anything about 4x4’s, but the following link shows how I replaced my 305 V6 with a 350 Chevy in my 1960 GMC. 60-62 frames are the same:

http://67-72chevytrucks.com/vboard/s...d.php?t=369663

Welcome to the forum, and good luck on whatever you decide to do.

Now this makes me feel better about the swap!!!!Thanks markeb01!!! That looks like something I can pull off. My only concern is since I am keeping my trans will it still be able to mount back up to its original location. I guess there is only one way to find out!! I have decided to pull it and swap it! thanks again for all the input and advice from everyone. This forum is my new home page. As for the 305 I will be parting her out.

[bhc41051]

You know you have a fairly rare truck. You just don't see to many 61 K model GMC's running around with the original motor. I would dearly love to have the original motor in my truck.

[Captainfab]

Swapping from the V6 to a small block Chevy is really very simple and does not require any specialized tools. Aside from your typical mechanics tools you will need an electric drill, assorted drill bits, a hammer and a center punch. With an original style '63-'67 pickup bellhousing for a Chevy V8 and a SM420, it will bolt in at the same location as the V6 bellhousing. If you need a bellhousing,let me know, I may have one.