crate engine or rebuild original 350?

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.

belay70

Junior Member
Joined
Feb 8, 2013
Posts
28
Reaction score
0
Location
Kansas City
First Name
Michael
Truck Year
1979
Truck Model
C20
Engine Size
350
Kinda two questions here -

1. What was my original engine horsepower rated at? Its a 1979 Chevy C20 with 5.7 350 and 3 speed manual 2WD. I found one reference that is might have been as low as 125hp?? Another mentions 175hp. Im astounded that stock horsepower would be that low on a 3/4 ton pickup designed to pull 12000 lbs....but then again, it was 1979 and rock was beginning to die. Things were different.

2. What is the usual/avg cost to rebuild a 350, back to factory spec? Im not interested in spending money on performance related items or upgrades. She has pulled a trailer full of metal fine, all these years, and I dont see a need to change that. Im not interested in racing, or showing off. I just want the engine to be as reliable and powerful as its been for the past 33 years. I need it to pull a heavy trailer with another car on it, repeatedly. It was originally built to do just that, and Im fine with that. Bearing that in mind, does anyone know the ballpark dollar amount for rebuilding this engine? I dont want chrome this and that. Just the basics. Understated engine dressing and competent performance.

thanks fellas.
 

Old77

Administrator
Staff member
Admin
Joined
Aug 19, 2010
Posts
28,220
Reaction score
8,591
Location
Kansas City, Mo
First Name
Jacob
Truck Year
1977/1990/1991
Truck Model
C10 longbed/R1500 Burb/R3500 Dually
Engine Size
350/350/454
I don't know "avg cost of a rebuild" as I'm sure it depends on situation but I can tell you what I did when deciding between a rebuild or crate.

My truck originally came with a worn out 305 so it was time to make this same decision. We sat down and lined out the cost of getting a 350 and rebuilding it and compared that to getting a 350 crate motor (which comes completely ready to go along with a 3 yr/36k mile warranty). Our analysis came up with that both would cost almost exactly the same (the rebuild was just slightly cheaper) WITHOUT factoring our time it would take as opposed to the Crate motor which is mostly "plug and play" if you get the right package. So we went with a crate motor. If I was to redo it today, I'd skip a 350 all together and go grab a complete 5.3/4l60e setup and rock the crap out of it but that'll be farther down the road for my truck as I can't justify it at this point.
 

89Suburban

Supporting Member
Supporting Member
Joined
Dec 7, 2010
Posts
24,454
Reaction score
5,614
Location
Southeast PA
First Name
Paw Paw
Truck Year
2007
Truck Model
Chevrolet Tahoe LT
Engine Size
5.3, 4WD
:popcorn:
 

Green79Scottsdale

Full Access Member
Joined
Aug 8, 2010
Posts
2,834
Reaction score
7,483
Location
G.R. - MI
First Name
Bob
Truck Year
1979
Truck Model
K20
Engine Size
400
I think Old77 hit the nail on the head. When you honestly sit down and figure the costs between the two, they are virtually the same. I know some people will say they can rebuild a small block for $300, I say bull$#!t. IMO, if you are going to rebuild you need to do it right. That includes magnflux for cracks from the beginning, bore and hone the cylinders, align hone the mains, and deck the block at least for straightness. Go talk to your local machine shop and see how much that is going to cost, and remember thats just to get the block ready. You start throwing in all the little parts you really don't want to reuse, and stuff adds up quick.

Although the other side of the coin is if you want the experience of rebuilding a motor yourself. If you want that, then I would say to rebuild. But do it with the understanding that you will look back and realize you could have just bought a crate motor.

Here is my personal view for my truck. When the time comes I WILL rebuild mine. But only because it is a 400, and for some reason it is just cool to me. Now if it was a 305 or 350, I would go with a crate motor (383HT :naughty:). The manufacturer has already done the leg work, you just need to drop it in and go. When you can get it from carb to oil pan, that seems like a great option, especially if you are on a short time table.

Sorry for the long winded post. Hope it made sense and didn't bore you too much.
 

belay70

Junior Member
Joined
Feb 8, 2013
Posts
28
Reaction score
0
Location
Kansas City
First Name
Michael
Truck Year
1979
Truck Model
C20
Engine Size
350
long winded posts are what Im asking for here....thanks for the input, seriously.

My initial feeling about the project was to restore as much of the original truck as possible, keeping the "soul" of the original truck. So rebuilding is my first choice. However, Im wary of spending the same amount of money and end up with something that doesnt run quite right, for some unknown reason, and which no one can figure out why.

Ive rebuilt an engine before - a little 60hp plant in a small vehicle from 1943 you might all remember as the original jeep. Ive also turned a wrench on a few other vehicles. I have a lift, many tools, a house with 4 garages, and no wife/kids. So Im not a novice, but Im no expert either.

Perhaps I was being naive, but I assumed I could do the basics and simply "refresh" her heart - honing out the cylinders, polishing the crank and cam, and replace the basic wear items like bearings and piston rings. I see kits at say, summit racing for around $200 that seem like theyd give me everything I need and then some. Realizing this ignores the heads completely....

Again, Im not looking to be flashy or high-powered in the end result. I wouldnt mind a bit more hp (I was shocked to learn that 165hp was the way it came) but its not required. She has pulled many heavy trailers just fine, as she is now. Your basic crate engines cost about $1500 and give about 260hp, and Im fine with that. But comparing $200-300 to $1500 is easy...

And what about the heads? My admittedly small understanding is that the hp is most drastically affected in the heads? Would I be asking for trouble if I performed the above on the block, and bought new heads?

A new carb and exhaust manifolds seem to be mandatory, regardless of what I do with the block itself. Anyone have suggestions for modestly-priced upgrades in either? I keep hearing how cheap these engines are to rebuild, make a believer out of me.

Also - does everyone replace the timing chain and sprockets during a rebuild?

talk about long-winded, jeez....
 

woodsrider250

Full Access Member
Joined
Sep 25, 2012
Posts
302
Reaction score
7
Location
Fredneck, MD
First Name
John
Truck Year
1974
Truck Model
C20
Engine Size
350-Qjet
Best of both worlds IMO is buying a built short-block only comparable to that GM/Jegs motor. Then vortec head it/cam of choice, etc. Point being to try to stay near that price benchmark, but make closer to 100 more HP.
 

Green79Scottsdale

Full Access Member
Joined
Aug 8, 2010
Posts
2,834
Reaction score
7,483
Location
G.R. - MI
First Name
Bob
Truck Year
1979
Truck Model
K20
Engine Size
400
I hope I offer sound advice here. Lets start with the beginning of your inquiries.

Yes you can just "refresh her heart". However, I would measure everything to make sure they are in spec. Is there a ridge at the top of the cylinder from wear over the years? Is the cylinder straight and square or oblong and tapered? No sense in doing a hone and new rings on cylinders that are out of tolerance. You will get bad ring seal. You can have a machine shop polish the journals on the crank, and I assume the cam to, but I am not sure about that.

I would check the flatness of the deck too. If it's not within specs, better to have the shop deck it flat. Do this with the heads too. While you have the heads off put new valve seats in them and have the valves polished if nothing else. 3 angle valve job and possible porting/polishing of the heads is an option, but not needed for what power level you are looking for. You could also buy new heads, that is perfectly acceptable. They will make better power than your original heads. We can get into that when you decide to rebuild for sure.

A new carb is not necessary. Might be smart to rebuild yours however, but you don't need to get a new one. Same with exhaust manifolds. If yours are in good condition you can reuse them. Reuse your intake manifold too. Of course this is all in the name of originality and price. For a nice upgrade go with Vortec heads and matching intake manifold. This upgrade is probably about a $1000 investment. As far as carb, I honestly can't give you a recommendation.

Yes do a new timing chain set-up. No reason not to use new parts there. You can also spec out a new cam to bump up your power a bit to.

Of course we are only covering the main components. It is a good idea to replace such things as starter, water pump, fuel pump, plugs, wires, and distributor. All these things add up, quickly I might add, to the final tally on price. Whether or not they are part of your "crate engine or rebuild" debate is all in how you want to look at it.

:cheers: By the way, I am going through this exact same situation with my Monte.
 

belay70

Junior Member
Joined
Feb 8, 2013
Posts
28
Reaction score
0
Location
Kansas City
First Name
Michael
Truck Year
1979
Truck Model
C20
Engine Size
350
Does this mean Ive got a 4-bolt main engine? block casting # is 39GM - 14016379

got the heads off tonight. and is orange varnish normal?

As I took off the long head bolts, the #5 cylinder intake bolt was milky brown - so I assumed a blown head gasket at that location, but once I got hte heads off, the metal gasket seemed to be fine. How do you look for evidence of a blown gasket when its metal?
 

Attachments

  • OB Resto 067_small.jpg
    OB Resto 067_small.jpg
    97.8 KB · Views: 254
Last edited:

belay70

Junior Member
Joined
Feb 8, 2013
Posts
28
Reaction score
0
Location
Kansas City
First Name
Michael
Truck Year
1979
Truck Model
C20
Engine Size
350
I guess Id rather have the guarantee and warranty of a bought engine, knowing I'll spend the same money on either scenario. But the act of restoration isnt about simply buying new parts and bolting them on. Its supposed to be hard, because thats what makes it fun/valuable/worthwhile. its respected because its hard. if it was easy, then everyone would do it. Saying you restored a vehicle by buying items and paying for service work to be done is ********. Now, if you simply cannot perform certain services like block washing, magnaflux, etc then Im fine with that. But the majority of work should be done by you, and I want to achieve that. I want to look back on the difficulty and heartache of the process, as I drive her down the road.

So, I have decided to rebuild the block I have assuming its not cracked or otherwise dead-ended.
 

MrMarty51

Full Access Member
Joined
Oct 25, 2012
Posts
7,439
Reaction score
9,170
Location
Eastern Montana
First Name
Martin
Truck Year
1978
Truck Model
K20
Engine Size
400
A big "IF" the cylinders are within spec of a simple rering do NOT hone the cylinders if they are clean without gouges and major scratrches.This is a very contrroversial issue,but,I rebuilt an engine just recently and decided that I was going to do the unthinkeable and try just one time to not hone the cylinders.
It works,I fired that engine up and it had the initial smoke of burning offd the oil and assembly lube and then it dried up,no smoke and has not used a drop of oil since.
I have spent a lot of time studying this and the " SAE "{Society of auto. engineers} had done an extensive study and rebuilt quite a few engines with 1/2 of them that had good cylinders and not honing those but honing the ones that would clean up and still be within specs. the ones that were honed used slightly more oil than the non honed engines anmd the non honed engines run farther before needing another rebuild than the honed engines.
An old machinist I had worked for kept telling Me,or asking "Why would anyone screw up a perfectly machined surface by honing" to which I was always real sceptic and would not think of assembling an engine without honing,after all how could the rings ever get broke in,and so with that last rebuild I just had to give it a try.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,008
Reaction score
8,977
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Does this mean Ive got a 4-bolt main engine? block casting # is 39GM - 14016379

got the heads off tonight. and is orange varnish normal?

As I took off the long head bolts, the #5 cylinder intake bolt was milky brown - so I assumed a blown head gasket at that location, but once I got hte heads off, the metal gasket seemed to be fine. How do you look for evidence of a blown gasket when its metal?

If you ask me, that #5 rod looks to be twisted on the crank journal too. Or is it the angle of the pic???

Edit, I guess that would be #3 looks twisted. The first one on the left in the pic. Angle of the pic maybe... :shrug:
 

Driver4r

Full Access Member
Joined
Jun 21, 2012
Posts
3,087
Reaction score
40
Location
Nebraska
First Name
Trevor
Truck Year
76,74
Truck Model
k10,c20
Engine Size
355/th350/np203, 454/th350/ff-rear
You can rebuild a nice 350 for around a grand.
Now if you want it to perform nicley. Your looking at a little more.
But reusing heads,rods,block,crank.
You can get a rebuild kit with pistons,gaskets,rings,and bearings for around 400-700 on the budget side.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,008
Reaction score
8,977
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
You can rebuild a nice 350 for around a grand.
Now if you want it to perform nicley. Your looking at a little more.
But reusing heads,rods,block,crank.
You can get a rebuild kit with pistons,gaskets,rings,and bearings for around 400-700 on the budget side.

That's pretty much a base budget like you said, and by the time you add your machine work, you're not getting it done for under $1000. Of course I have extra things done, like rods reconned, triple angle valve jobs, rotating assembly balanced etc etc. I don't skimp on full motor builds. It just doesn't pay not to. The extra adders is what runs the cost up, but it also what set your build up above the rest, and it's considered insurance.
 

MrMarty51

Full Access Member
Joined
Oct 25, 2012
Posts
7,439
Reaction score
9,170
Location
Eastern Montana
First Name
Martin
Truck Year
1978
Truck Model
K20
Engine Size
400
That's pretty much a base budget like you said, and by the time you add your machine work, you're not getting it done for under $1000. Of course I have extra things done, like rods reconned, triple angle valve jobs, rotating assembly balanced etc etc. I don't skimp on full motor builds. It just doesn't pay not to. The extra adders is what runs the cost up, but it also what set your build up above the rest, and it's considered insurance.
:waytogo:
 

Latest posts

Forum statistics

Threads
41,859
Posts
903,650
Members
33,372
Latest member
83elcowes
Top