All 70 Corvette engines came with steel cranks and 4 bolt mains. It was the last year for both on the base motor.

 

The '70 350/300 I tore down was 4 bolt main with a cast crank. Nobody had been there before.

 

This is great! The links are very helpful.

I'd be okay in the 5-6k range. After hearing feedback it seems unavoidable if I'm going the crate route.

Would the engine you sent fit right into my C3? And what's the difference in the one you linked and this one: https://blueprintengines.com/product...pr_seq=uniform

 

Y'all are giving me too much credit. I just want the simplest option - a crate. To go with a rebuild would require expertise I don't have and/or an exorbitant amount of trust in my mechanic/the people helping me on it. It's just not possible. I know a rebuild will cost more but I'm willing to pay a little more the simplicity/peace of mind of the crate.

 

Yeah my mechanic did not mention Blue Print but I'm liking what I hear from what you guys have posted. I can't even find a place with a price for a GM motor. Anybody got a link just so I could see the options GM has?

 

Thanks for this! Could you direct me to a site or some links with some good LS options that would fit my C3?

 

GM
https://www.chevrolet.com/performanc...nes/350-engine
dealer pricing will vary, available at your local dealer

Blueprint:
Generally your best bang for the buck, quality build, good warranty, less than GM. But less warranty. Most other builders have thinner warranties.
The 341Hp blueprint you mentioned is a good choice: I like the cam etc.
https://blueprintengines.com/product...pr_seq=uniform

But I would not bother with the fully dressed version.
It will not fit a 69 std hood C3.
Get the long block version.
The intake is far to tall at 4.5". You need 4.0" or less. PGet a Performer 2101, 2104 or 2701, depending on heads & carb.
The air cleaner is far too tall.
Use your factory one, or get a GM low profile with a 2" drop from a Corvette Vendor, not the internet.
If you have a good QJet, KEEP IT. Throw that Holley away. Or why buy it?
You would be FAR better off sending a running Qjet to Lars on this forum for a world-class rebuild, like none other.
For less than a new carb, that will not be as good.

Here is the long block version I would get:
https://blueprintengines.com/product...pr_seq=uniform

Almost every single intake manifold on the market is too tall for a C3, except the few I mentioned, and a couple others.

Take a pic of you engine, carb & air cleaner here, and we can help.

 

It's pretty much a bolt in but there's a few things that you need to be aware of. You'll probably need the one piece rear seal style flywheel or flex plate and other thing is you may need to elongate the A/C mounting brackets due to the raised exhaust ports. According to Blueprint the exhaust ports are raised a 1/2 inch however I found the exhaust manifold/header holes were only a 1/4 inch higher than stock.
The only difference between the two engines is the deluxe dressed comes with more peripherals like a water pump and air cleaner that doesn't fit our cars, a steel braided fuel line (I made my own hard line), plug wires (I cut mine to length), etc so no reason to spend extra money on things that not useable.

 

My 70 ZQ3 engine has a January build date and has a steel crank. I wonder if the cast crank was a change later in the model year.

 

leigh, does the early Corvettes have a lower hood than the later cars? I ask this because I have the 4.595" intake manifold along with a 2.75" net height from carburetor flange air cleaner with 3/4" hood clearance

 

My '70 350/300 has a build date of May 13, 1970.

Cast or steel crank?

Thanks

 

A "crate" engine is just an engine that comes in a box. A used, running engine that you buy on Facebook, or from a local junkyard (perhaps with a warranty), may do everything you need. You can ask them to put it in a box. I'm shocked that your mechanic is willing to install an engine for you, but doesn't have a source of inexpensive crate engines (which he can choose to mark-up or not).

With a few expensive exceptions, the only way to get a "new" engine is to buy one from GM. Below is the link. If you see something you like, you can (no kidding) order it from your local Chevy dealer. Or you can use the 8-digit part number to find a reseller. Jegs, Summit, Pace Performance, Scoggins-Dickey, and Speedway Motors are a few I can think off off the top of my head. The GM website has installation instructions, and a dealer locator. This is NOT a cheap option. If you do go with an LS, consider an LS3 long block, and then get a low profile intake to fit under your C3's hood.

https://www.chevrolet.com/performanc.../crate-engines

Watch this video before you decide you can't refresh an engine (I didn't say rebuild, you aren't touching the crank or cam, but on an LS, that can last 300,000 miles). Compared to a Gen 1 SBC, they go together like LEGOs.

 

OK, so when ex ports are raised 1/2" on the engineering drawing: its an sbc so exhaust flanges are at 45 degrees from Both vertical & horizontal.
Then use cosine of 45 = 0.7071. So 0.7071 x 1/2" = about 0.354"
If using 0.500" raised ex ports, each header flange is moved UP about 0.354" AND it's Also moved Outboard about 0.354"
The entire header moves Up & Out about 0.354"

 

I could use a guy like you when I'm trying to figuring out what angles to cut my crown moldings on.

 

The one part I will ask to really reconsider is the thought concerning, "I don't need crazy power. I just want the power and perk of the original car". Are you sure about that? I get that you're not looking to build a temperamental hard to cruise racer here but when a stock issue do over of a 350 or 327 to original spec makes your corvette move out with less authority than your "daily driver" current era family car you might just come to regret setting the bar so low.
Your $4,000-$5,000 self imposed budget will limit your choices. Just a few years ago a Blueprint engines 383 with a roller cam and their own 195cc heads could have been purchased inside your budget but today you'd need pony up a little more for it. Still a pretty good deal though for a ready to rock street engine despite the higher MSRP today. These engines are fully capable of bring any C3 into the 21st century expectation for "GO" without having to suffer the slings and arrows of Computer control, fuel injection and sensors to make it all happen. Nothing wrong with any of the modern equipment but if you want o keep it period correct with a Carb and basic tech, concerning ignition and fuel, from the period this is a great way to go. a 3 year warranty and a proven matched parts selection that has a big wide torque curve and near 450HP is tough to beat for the money spent.
A few more bucks spent can get you Blueprints own 400in engine. Forged internals and a new block all add up to a 500+ HP killer SBC combo.....this one is well outside you're budget but I've had one of each of these engines delivered over the last 8 years and dropped them in a couple of my cars. Neither will disappoint. Both are strong performers that I feel are well worth stretching that budget for a bit more.
Some here have advocated for GM's crate engine offerings. I've seen them and have friends that went this route. They work GREAT too. Yet, as is often the case, if money matters you simply can't get as much engine or power for the money spent with a GM crate engine as you'll get with the BPE offering that is most similar.

 

I can assure the OP that the Blueprint 350 341HP ain't no slouch. I ran a 14.75 at Gainesville raceway with my L-83 CFI. Although I have never been to the track since installing the Blueprint 350 341HP, it runs circles around that L-83 CFI. The Blueprint 350 390HP version is the same engine as the Blueprint 350 341HP except for the camshaft.

 

It was my understanding that all 1970 engines had a steel crank. I guess I need to do some more research to when/if there was a change.

 

My older BP engine is a 355ci, its a used block bored over. The ones you see advertised as 350ci are new blocks, many of which were purchased from GM, I think they are changing where they get them now...not sure... Any questions give them a call...

OP: I'd say to get the Long block but then you would have to trust someone to put the manifold and etc on it... Call Blue print and see if they have someone who can help with clearance issues and advice...

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I asked Blueprint about this and the SBC blocks are new casting sourced from American and German foundries.

 

JMO: ain't but one way KNOW what's inside vintage iron; look-see.

As for crown molding and the like; it took me years to put those trig courses to some practical, personal use. The basics can be helpful.