91 350 into my 70?

[TXGreaseMonkey]

Hey guys, I have been browsing the forum for quite some time, just haven't piped in much since joining. I bought a '70 C10 LWB a while back...PO said it had a 'new' GM Goodwrench crate motor with a 'new' TH350.

Long story short, the motor blew on the 2nd day owning it (I even checked that it had oil)..so I've pulled the engine/trans a few months ago.

While looking into crate motors, I just want the truck running for now.
Locally, someone is selling a 'running when pulled' 91 Suburban 350 for cheap. It was over heating, he pulled over, and didn't run it anymore. Thinks its just the head gaskets. Said there was no external leaks and ran smooth right before being pulled.

Will this engine swap directly into my '70 C10? Fuel pump housing, cool locations, etc?

I've already discussed some of the newer Vortec 350s swapping in (96+)
but they're not cheap enough to gamble, where I can just get a new crate motor for the price.

thanks for any info and if this is in the wrong area, please move it. I searched the site for similar keywords/swaps and didn't come up with much specific to my case

[notsolo]

Is it TBI or does it have a carb? Throttle body is going to need computer and wiring, fuel pump in tank.

[TXGreaseMonkey]

My goal would be to make it carbed either way...would it matter if/can I bolt on my carb intake manifold to it? I just want a functioning bottom end I can bolt in and go for now. I'm waiting on better pictures, he only had the one and it wasn't very good

[Coley]

...this possible donor motor was overheating? ....and he didn't run it anymore?....and he thinks it might need head gaskets?....that's seems a bad bet to me.

I would say that motor, in all likelihood....needs a rebuild....which means you will have (2) motors that need work.
There are lots of running small block motors out there for not much money.

The choice is yours...but there is no way I would assume that $40 worth of head gaskets was going to put your truck back on the road for a year or two....the odds of that are very, very low.

...just my two bits, its your decision.

how about this:
Put out your own ad for a running, quality small block (350) in your local ads of choice and see what comes back....you'll probably be surprised at what is out there and then you might have your pick of the pack.

All good
Coley

[truckster]

Unless I plan on a complete rebuild of a motor, I don't buy it unless I see and hear it run.

As far as one that was overheating and might just need head gaskets...

[TXGreaseMonkey]

That's a good idea actually...a 'Wanted' ad instead of just searching for Sale ads.... FB marketplace has a lot of items popping up regularly, and craigslist is about the only main one I use. I search it nearly daily. But so many people sell stuff with limited details that I have to pull out of them, and I have actually gotten burned on engines before for other projects...

I mainly just wanted a running bottom end I can toss my manifold and carb on and go.. for all the efforts I may just bite the bullet and get a new/reman'd crate motor with a warranty... but that's a good tip, Ill see about putting out a wanted ad

[webfoot]

As popular as LS swaps are I'd think a roller motor SBC could be had at the right price if you're patient enough.

Any "ran when pulled" motor is a gamble.

[TXGreaseMonkey]

I guess with this particular engine aside, do these engines swap right in... in the event I find one running/good condition? Intake Manifold/Distributor, bolt up to my TH350, external fuel pump, etc...

I'll keep searching the forums for these answers, but its not always specific to a year...there are a lot of variations to which engines require which modifications to make them truly 'bolt in'.

Thanks again

[TXGreaseMonkey]

I have searched the Engine/Trans area and have not had much luck... does this forum have a thread where all engine compatibilities are tossed into a single thread?

Like which year donor trucks can be from and what mods need to be done to bolt it in and go to earlier year trucks? We've had this on many other forums for platforms Ive had over the years, curious if theres one here I can just read up on and narrow down which engines to keep an eye out for.

Appreciate the help so far, I think you've convinced me to pass on this cheap engine since I don't want to gamble on needing another rebuild...I.E. a second sbc 350 sitting in my garage in parts... my wife would LOVE that ^_^

[webfoot]

Everything up until the LT is a SBC, even a LS bolts up to a 1970 chevy bellhousing.
The vortec stuff uses different heads and intake but bolts to a sbc block.

[TXGreaseMonkey]

Originally Posted by webfoot

Everything up until the LT is a SBC, even a LS bolts up to a 1970 chevy bellhousing.
The vortec stuff uses different heads and intake but bolts to a sbc block.

What about little things like exhaust manifolds, fuel pump location, motor mounts, oil pans and filters, etc? My C10 also has power steering and A/C, the bolt locations for all this is the same too right? I actually want to keep it carbureted for now, I like tinkering. The Vortec's are very appealing with swapping in the proper IM, and making it carbureted.. but the little things like I mentioned above are what I've never really seen much on.

Appreciate the info

[MARKDTN]

To answer your question, yes that engine will bolt in in place of your 350. You have to use the flexplate on it and not your original because the 1-piece seal engines use a different one. You may or may not have machining for the fuel pump rod; so you may be forced into an electric fuel pump. You will have to have a different intake because the center bolts are at a different angle or you can slot the manifold severely and make them work. Either use all or none of the serpentine belt system and water pump-and fan. The exhaust manifolds will bolt right up.

Now, as to overheated a little and then quit, I doubt it. In about 2001 I bought a '95 Suburban. two weeks later my wife was driving and the water pump died. It got so hot that it melted the plastic plug on the water temp sending unit. Put a new water pump and sending unit and put almost 100K miles on it after that with no real issues. Small Blocks are tough! One reason they are a top choice in demolition derbies-that and rear distributors. I would walk cautiously on this engine. Also, I would keep the TBI. It is very reliable and simple to hook up. You will gain nothing converting it to a carb and you would have all the parts to do it except a fuel pump.

[webfoot]

That is what I'm trying to say. it is all "SBC" so it is interchangeable, other than the aforementioned differences to vortec stuff.

The ones that used electric fuel pumps probably used a fuel pump block off plate, but I've never seen one and can't comment. If there are pics of the motor you can look for it in the usual location.

[clay68c10]

Just a bit more info;

My 93 has a block off plate for the fuel pump. I’d guess the block is probably drilled for the push rod or they wouldn’t have bothered to block it off.

Some Vortec blocks have the boss cast, but no plate and definitely not drilled.

I doubt the TBI cam has the lobe to drive the pump. The Vortec cam definitely doesn’t.

[TXGreaseMonkey]

Originally Posted by clay68c10

Just a bit more info;
I doubt the TBI cam has the lobe to drive the pump. The Vortec cam definitely doesn’t.

That's an interesting point there... even if the newer engine has the block off plate for the pump...I may have to change the Camshaft to get a functioning fuel pump... which leads me to take a look into how easily an electric pump can be mounted/plumed instead..

[MARKDTN]

Originally Posted by clay68c10

Just a bit more info;

My 93 has a block off plate for the fuel pump. I’d guess the block is probably drilled for the push rod or they wouldn’t have bothered to block it off.

Some Vortec blocks have the boss cast, but no plate and definitely not drilled.

I doubt the TBI cam has the lobe to drive the pump. The Vortec cam definitely doesn’t.

Pretty sure at least the early TBI cams do have the eccentric. The earlier ones have a better chance of having the blocks machined for the pushrod too in my experience. Just take that cover off and look if it has one. If no cover you know it isn't machined.

[truckster]

Originally Posted by TXGreaseMonkey

That's an interesting point there... even if the newer engine has the block off plate for the pump...I may have to change the Camshaft to get a functioning fuel pump... which leads me to take a look into how easily an electric pump can be mounted/plumed instead..

My 5.7 Vortec had the block-off plate but the cam didn't have an eccentric. I changed the cam (HT 383 cam) so I could use the mechanical fuel pump.

[TXGreaseMonkey]

Originally Posted by truckster

My 5.7 Vortec had the block-off plate but the cam didn't have an eccentric. I changed the cam (HT 383 cam) so I could use the mechanical fuel pump.

good to know! I'm not completely turned off from using an electric pump, but I wanted this truck to keep it as original as possible and learn to tweak on it as an original carbureted motor.