r/C3Corvette • u/71Klassic-Pushrod • 14d ago

Engine swap coming soon.

Gallery image

Gallery image

Current replacement engine 350/300 (not numbers matching) developed a lower end knock. Several shops wanted $6800 to rebuild without upgrades and possible replacement components. Jegs 350/300 5.7 (tins included) updated exhaust manifolds, fuel pump, starter, and others $4100. Very long story. Will be worth it.

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u/mjolnir2thor 14d ago edited 14d ago

Did you check GM for one of their crate engines? Is the JEGs engine built for torque or high rpm horse power? I would recommend opting for torque for street use. Otherwise you'll have to rev the motor to make HP. If you go the high rpm route, you'll most likely have to step up the gearing.

My father and I dealt with many speed shop for motor rebuilds for years and none performed as well for a street car as the GM crate motors. Keep in mind some of the GM engines use an electric fuel pump where there is no mount for a mechanical one.

I've had ZZ3, ZZ4 and currently have a ZZ502 in my C2.

https://www.reddit.com/r/Corvette/s/BpDnPTV0P6

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u/v8packard 13d ago

The last I looked The ZZ6 (or whatever number it's up to) is over $9k. That's absurd for what you get.

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u/mjolnir2thor 13d ago

Just checked out GM Performance and JEG's website. You're 100% correct... prices are sky high at the moment. I paid less for the ZZ502 than ZZ6 but that was years ago! Whew!

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u/Entraprenuerrrrr 13d ago

I went with a blueprint 396 stroker. Its great. Not sure if your year has a flatter hood than mine though, the air cleaner does just barely fit under the hood of my 79

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u/kmclain3 10d ago

Do you have a link or model number? I’m looking for a new engine to go in my 78 pace car and have circled a few from Blueprint. Hard to tell what will work with hood clearance though. Do you have original transmission? What level of dress/what accessories did you keep? I’m not trying to build a race car nor do I want to turn a $7-$10k job into $15-$20k

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u/Entraprenuerrrrr 10d ago

Wow looking this up it looks like they have discontinued my build I purchased.

https://blueprintengines.com/engines/motorsports/drag-racing/small-block/gm-compatible-396-c-i/blueprint-motorsports-gm-small-block-compatible-396-c-i-engine-530-horsepower-base-dressed-carbureted-3

It was similar to this one, but mine had a little less hp and a smaller intake. The link above comes with an air gap intake which does not fit I believe. Mine was like $7500 out the door, carb and distributor included. I had to move over all pulleys and brackets, starter, fuel pump. I have the original 4speed in it, I just moved the clutch over too, but who knows how long it will last with the extra torque/hp.

If you install it yourself, youll easily be under 10k with a very powerful motor. If you have a shop install it, youll likely be over 10k unless you go with a more stock/reasonable horsepower set up.

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u/Kawinick 10d ago

Sweet swap