1975 K10 Engine Swap Questions

[NebraskaRanger]

Hey everyone. So I am the new guy here. So I'll introduce myself.

I'm Levi. 22 year old graphic designer at Cabela's here in Nebraska.

I just recently bought a 1975 K10. This truck is absolutely beautiful. I love it a lot. However...I managed to seize up the engine (305) within 4 days of buying it. I am not a smart human being. I have tried manually turning it over, push starting it, nothing has worked. So it's lead me to believe that it's screwed and I should start searching for a new engine. I told my dad about my situation and he told me that he has a 1979 K10 with a rebuilt 350 out at the farm. He said it ran when he parked last year, so it might need some TLC, but told me I could take the engine out of it and put it in the 75.

Now, as you could probably guess by my job title, I am no mechanic. I have read up on 305 to 350 swaps on here, but none of it really makes sense to me. From what I read, everything should bolt right up. But there is talk of TBI, sensors, headers, etc. that throws a wrench in my head.

So, explain like I'm 5...what do I need to know about doing an engine swap or things that you wish you knew when you did yours?

Thanks in advance. I appreciate it!

(Also, if there's a post that has pretty much everything I need to look at, please feel free to link to it.)

[83swb]

Let me begin by saying that both the 305 and 350 share all the same external characteristics, to make it short the 305 is just a smaller displacement 350. As long long as both motors are Gen1 (First generation chevy small block), which they should be considering both trucks are the same vintage, EVERYTHING should be a straight over swap. When I say straight over I mean that with the engines out of both trucks the "new" motor would bolt in the engine bay exactly the same as the other. You may run into very minor issues in the swap, distributors may be a different style requiring that you modify the power and tachometer connections, exhaust manifolds may be different or one may have headers, you may have to modify your fuel line etc. You should be able to leave all the accessories on the motor while doing the swap if everything on the other motor is in operating condition (IE alternator, power steering pump, water pump, pulleys). Of course you'll run into other small issues during the process but its all part of the learning process. That being said, a shade tree mechanic could probably do the swap in a day and change.

It wouldn't hurt to buy a haynes service manual or something similar.

[73Super8]

I'll subscribe. Might learn something.

[andrewmp6]

It should be a 99% bolt in but like said something small will pop up you have to make work.

[86c20]

i have to ask is it the motor wont run or it wont turn over? no need to repace a motor for a bad coil or lose wire. plz give more details about what happend.

[Dead Parrot]

Any idea why it seized? Lack of oil? Got too hot? Loud clanking/grinding before it stopped? You said you tried push starting, so it has a manual transmission? Keep in mind that on a 39 year old truck, almost anything can fail. Wore out brushes on the starter can cause that to do nothing, no clicks or anything. Went through that a couple of weeks ago. If you got it too hot due to a stuck thermostat, you can crack a head gasket and possibly hydraulic lock a cylinder due to coolant leaking into it. You can pull the spark plugs to check for excessive fluids.

If you decide to swap the motors, verify the donor motor is worth the trouble before doing the swap.

A good camera is your friend. Take lots of pictures. Both of the donor truck and yours. Very helpful when trying to figure out where that weird wire or hose goes.

Clean and degrease both motors before starting.

Plan on needing at least $200 in various small parts to complete the job. Just seems to work out that way.

Consider taking the transmission to a shop for inspection and possible seal replacement. If manual transmission, also have the clutch checked out. You will have most of the removal/installation work done anyway as part of the motor swap.

[donut]

Welcome Levi, I'm kinda intrigued as to your dilemma.
First thing I would recommend in a Chilton's/Haynes manual from your local auto parts store, education is a major factor and can help down the road, (plus lotsa pictures...)

On this site, go into your user CP, make up a signature with pertinent specs of your truck, and/or post exactly what you have. Transmission, highly modified etc, can make a difference.

Trying to turn it over, do NOT do it by the bolt in the harmonic balancer. This bolt breaks and you have potentially bigger problems.

Ok, we know your lacking on the knowledge part, no biggee, we all had to start somewhere. What's your tool situation? Do you have a place to work on it and leave it until your done? Jack, jack stands, potentially a hoist.... How about a digital camera? Take pictures for reference so you can put it back together, and so you don't have to post a "where does this wire go", thread.

Whatever you do, work safe.