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305 in my Vette


Kerry

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My 80 Corvette has the 305 in it. Any ways to beef it up with out doing a motor swap? California car so it has all the additional smog stuff. Should I pull all of that off ?

New to Corvettes so sorry if it is a dumb ???

Thanks

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There's not much you can do. To beef up the power a bit, the 80 305 Vette's came with headers. You can do an edlebrock intake, better carb (600 cfm...maybe 550), and a good air cleaner. There's not much else, unfortunately. They just can't breath. You could buy a set of 305 Vortec Heads...It'll help, but you'll probably never dip below 14 secs in the 1/4. An engine swap is absolutely your best bet. 350s are a dime a dozen, it doesn't cost much to have them machined and rebuilt, and everything from the 305 will bolt right up.

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I would just add that if it were me I'd yank the 305 and do a 383 swap but I'd store the original 305 if you ever want to sell the Vette as numbers matching.

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Are the 80 305's from California dual exhaust ? My car is not here yet so I don't know if it is dual or not ?

As for a swap...I am no mechanic and could not do it myself. And shops charge to much !

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Are the 80 305's from California dual exhaust ? My car is not here yet so I don't know if it is dual or not ?

As for a swap...I am no mechanic and could not do it myself. And shops charge to much !

It's not "True Dual" It's got a Y-pipe from the headers to a single exhaust, through a cat, to a muffler, which comes back out dual. Without sidepipes, it's hard to run dual exhaust on these cars. If you run side pipes with a 305 you'll lose more than you gain though. Your low end torque would probably drop significantly.

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I have to agree with Eddie44, a 383 swap is a good way to get some power, and keep the block in storage for originality sake. You can get a 383 crate motor from GM with a warranty, and beef it up all you want.

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I have to agree with Eddie44, a 383 swap is a good way to get some power, and keep the block in storage for originality sake. You can get a 383 crate motor from GM with a warranty, and beef it up all you want.

Just so you know, a 383 is a 350 with a 400 crank and different rods (3.75"?). Definately the best bang for the buck if paired with the almighty vortec heads and an airgap intake. Throw in the right cam and you've easily got 450 hp.

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You can do a true dual on the 80 through 82, here is how I did it on my 82.

The homebuilt X-pipe is right were the catalitic converter used to be... I still had the 02 sensor in there as well.

Out back I had a set of Borla's and it had a real nice low rumble at idle.

I agree, rip out that 305 and there's a million other motors that will bolt right in from a 355 all the way up to a bored and stroked 402. The swap would be pretty easy to do with the right tools.

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I have to agree with Eddie44, a 383 swap is a good way to get some power, and keep the block in storage for originality sake. You can get a 383 crate motor from GM with a warranty, and beef it up all you want.

Just so you know, a 383 is a 350 with a 400 crank and different rods (3.75"?). Definately the best bang for the buck if paired with the almighty vortec heads and an airgap intake. Throw in the right cam and you've easily got 450 hp.

I get 430HP on the ground with mine.......... :3gears::thumbs

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You can do a true dual on the 80 through 82, here is how I did it on my 82.

The homebuilt X-pipe is right were the catalitic converter used to be... I still had the 02 sensor in there as well.

Out back I had a set of Borla's and it had a real nice low rumble at idle.

I agree, rip out that 305 and there's a million other motors that will bolt right in from a 355 all the way up to a bored and stroked 402. The swap would be pretty easy to do with the right tools.

I'll take that as an offer to swap the motor for me........lol

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I know......Just had to say it though. If and when the time comes, everyone here will know it.

Desertdawg...

I thought you had to have the cat to be legal in this state. Am I wrong ???

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I know......Just had to say it though. If and when the time comes, everyone here will know it.

Desertdawg...

I thought you had to have the cat to be legal in this state. Am I wrong ???

Shhhhhh!!! What they don't know won't hurt them.

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I know......Just had to say it though. If and when the time comes, everyone here will know it.

Desertdawg...

I thought you had to have the cat to be legal in this state. Am I wrong ???

Depends on where you live, and how you use the car.

If you try to push it through emissions normally, yes, if they look. Don't know how not having cats affects the emissions output of the infamous LG4.

If you register as a collector and get collector insurance, then you could be emissions exempt.

That's basically the short version of it.

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I live outside of the testing area.

But there's no reason you couldn't use cats and still go with duals.

Here's some good hi-flow cats, I just picked up a pair of 3inch off of ebay for $100 I bet you could fit both of them in the space of the original cat.

Or the illegal version, cut your stock cat in half, take a couple of these, ... you should be able to lay the ovals side by side through the middle of the stock cat housing, weld a round pipe over the ends and hide the fact that there is dual pipes inside your cat instead of the plug-em up stuff...

Idea's, I've got 100's of them running around in my head..... :chris

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