Crate Motor swap Info Help - 1960 GMC K1000

[TRybas]

Hello All,

I have a 1960 K1000 with original 305A and SM420. I am considering swapping out for a crate motor and trans. I am looking for bolt in/ turnkey. She is as original as possible and I want the ability to make her whole again one day.

Years ago, I recall a thread/ build journal of someone doing so on their ’61 4x4 but cant find it. If I recollect it was a little more complicated for the 4x4? Any insight or point me to where I can read up would be greatly appreciated.

Thanks,
Tim

[AZKen]

Well, it can be done of course. If you don't find a "How-To", you would do it the normal way. Mock up. Glad to help if you get to that.

But these are the questions at that time.
"Bolt in" is a relative term. Needs discussion.
"Turn key", relative. Needs discussion.
"Crate motor" "and trans" Needs more info.
Only slight 4x4 issue is Xfer case hook up.
Mod skills, tools, space, time and willingness are necessary.

[lizziemeister'sV6]

My big question is " Where do you get a crate GMC V6 engine?" All of us would be interested in that.: upyes:

[AZKen]

I don't think it's a GMC V6. He is just trying to be discrete. Not ruffle feathers. Key word: Swap.

[Prowbar]

I saw some pictures of your truck and couldn't help but wonder why you wanted to swap out a freshly painted (rebuilt?) engine? If you need more power, consider freshening up and swapping in a larger V6 like a 351 or 401. That is a true bolt in swap!

[George Bongert]

Originally Posted by TRybas

Hello All,

I have a 1960 K1000 with original 305A and SM420. I am considering swapping out for a crate motor and trans. I am looking for bolt in/ turnkey. She is as original as possible and I want the ability to make her whole again one day.

Years ago, I recall a thread/ build journal of someone doing so on their ’61 4x4 but cant find it. If I recollect it was a little more complicated for the 4x4? Any insight or point me to where I can read up would be greatly appreciated.

Thanks,
Tim

Greetings TRybas!!

First, why are you looking to replace that 305A V-6 and SM420 Transmission, and what are you looking to replace them with? Second, and I know that it has been done by many, is to swap out the original GMC big Block V-6 and replace it with an SBC 350 V-8. In my opinion, THAT is a sacrilege that spoils the authenticity and the collector value of the Original GMC Truck. In my case, I switched out an inferior Chevy 292 I-6 in favor of the GMC 305 V-6 which made my old Chevy Truck much more dependable and reliable, and increased it's overall value. I'm not telling you what to do, since it is your truck to do with as you please. All I'm saying is is if it were my truck, I'd leave it original. That 305 V-6 and SM420 Transmission will only increase the truck's value should you ever decide to sell it.

[TRybas]

Thanks all for the feedback and concerns. Does anyone have experience specifically with a 4x4 swap? Id like to keep the 4x4 capability but imagine it’s a different can of warms from 2wd. Namely the short distance to the divorced transfer case.

The main reason for wanting to swap aligns, in principle, with everyone’s concerns. I like to drive her but want to preserve the original motor. I am a stickler for restoring/ preserving her to factory hence the “bolt in” requirement (shout out to AZKen for sourcing a bunch of those parts over the years).

Second, is all the reasons people on here hate to hear; I like to drive her so ease of use, comfort, little extra speed, and drivability. I could be wrong but I suspect aftermarket add-ons like A.C. and power steering will be easier to source/ install without concern of altering the original motor.

Third, I’ve got a slight coolant leak, I’m hoping its just a head gasket that didn’t seat right but I suspect the machine shop messed up and didn’t surface the heads, block, or both. I’m doing my homework now incase that is the issue. If its easy enough (bolt in turn key) and can be done for $4-6k over a 4-6 days I’d rather do it than wait the 4-6 months to get the original back.